Social play experience in juvenile rats is indispensable for appropriate socio-sexual behavior in adulthood in males but not females

Classified as probably not a substantial claim.

Interaction with a conspecific across a similar physical barrier has been shown to be socially rewarding.

“Interaction with a conspecific across a similar physical barrier has been shown to be socially rewarding (Peartree et al., 2012)”

• cites Peartree et al., 2012 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Juvenile social isolation in rats leads to impairments in cognition.

“cognition (Einon et al., 1978; Baarendse et al., 2013; Yusufishaq and Rosenkranz, 2013)”

• cites Einon et al., 1978 sourceNot checked — no full text of the source
• cites Baarendse et al., 2013 sourceSupported
• cites Yusufishaq and Rosenkranz, 2013 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Studies investigating neural underpinnings of this behavioral sex difference have identified various nodes within the larger circuitry of social behavior, including the medial amygdala and lateral septum, which exert sex-specific influences on play following sexual differentiation early in life as part of typical brain development.

“Studies investigating the neural underpinnings of this behavioral sex difference have identified various nodes within the larger circuitry of social behavior, including the medial amygdala (VanRyzin et al., 2019) and lateral septum (Bredewold et al., 2014), which exert sex-specific influences on play following sexual differentiation early in life as part of typical brain development.”

• cites VanRyzin et al., 2019 sourceSupported
• cites Bredewold et al., 2014 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Deficits in play are core symptoms of neurodevelopmental disorders like autism spectrum disorder, attention-deficit/hyperactivity disorder, and early onset schizophrenia.

“Indeed, deficits in play are core symptoms of neurodevelopmental disorders like autism spectrum disorder, attention-deficit/hyperactivity disorder, and early onset schizophrenia (Alessandri, 1992; Jones et al., 1994; Møller and Husby, 2000; Jordan, 2003; Helgeland and Torgersen, 2005)”

• cites Alessandri, 1992 sourceNot checked — no full text of the source
• cites Jones et al., 1994 sourceNot checked — no full text of the source
• cites Møller and Husby, 2000 sourceCould not verify

  The Behavioral Dimensions section identifies school or work impairment, shifts in interests, and social withdrawal as potential features of the schizophrenia prodrome, but does not identify deficits in play. Searches for play, childhood play, early-onset schizophrenia, autism, and ADHD found no passage addressing the attributed claim. The available passages have no page numbers. (LLM, conf=0.73)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Many neurodevelopmental disorders also exhibit robust sex differences in diagnosis and symptomology.

“many of which also exhibit robust sex differences in diagnosis and symptomology (Aleman et al., 2003; Ramtekkar et al., 2010; Arnett et al., 2015; Halladay et al., 2015; Giordano et al., 2021; Prosperi et al., 2021).”

• cites Aleman et al., 2003 sourceNot checked — no full text of the source
• cites Ramtekkar et al., 2010 sourceNot checked — no full text of the source
• cites Arnett et al., 2015 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Juvenile social isolation in rats impacts susceptibility to addiction-related behaviors.

“impacts susceptibility to addiction-related behaviors (Whitaker et al., 2013; Baarendse et al., 2014)”

• cites Whitaker et al., 2013 sourceSupported
• cites Baarendse et al., 2014 sourceSupported

May combine two claims.

Isolation prevents all social interaction-both play and non-play-so it is unclear whether identified impairments are due to lack of play vs. lack of general social interaction, as well as additional stress that total isolation induces.

“First, isolation prevents all social interaction—both play and non-play—so it is unclear in most of these studies whether and to what extent any identified impairments are due to the lack of play vs. the lack of general social interaction, as well as the additional stress that total isolation induces (Begni et al., 2020).”

• cites Begni et al., 2020 sourcePartly supported

  The Discussion reports that deprivation of social contacts impairs neuroplasticity in rats, supporting the claim that isolation removes social contact and can produce impairments. The paper does not distinguish lack of play from lack of other social interaction as causes of those impairments. It also does not establish that total isolation adds stress in these animals; the Discussion reports no altered wellbeing from isolation housing itself and describes resocialization as a temporary stressor. The indexed passages have section labels but no page numbers. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

May combine two claims.

The ability and motivation to participate in play was intact in BARR and ISO animals and was increased relative to historical data for control-housed animals.

“we found that the ability and motivation to participate in play was not only intact in BARR and ISO animals but was increased relative to our historical data for control-housed animals (Figure 1C; Argue and McCarthy, 2015).”

• cites Argue and McCarthy, 2015 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Interaction with a conspecific across a similar physical barrier reduces anxiety-like behavior as compared to full isolation.

“and to reduce anxiety-like behavior as compared to full isolation, an additional benefit (Klapper-Goldstein et al., 2020).”

• cites Klapper-Goldstein et al., 2020 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Recent work in Drosophila identified a transcriptional regulator believed to govern this same effect, suppressing aggression in a social experience-dependent manner.

“Indeed, recent work in Drosophila identified a transcriptional regulator believed to govern this same effect, suppressing aggression in a social experience-dependent manner (Ishii et al., 2022)”

• cites Ishii et al., 2022 sourceSupported

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

Independently assessing males and females and noting a sex difference if an effect is observed in one sex but not the other is a common misconception of the appropriate way to assess sex differences.

“This was as opposed to independently assessing males and females and noting a sex difference if we observed an effect in one sex but not the other, a common misconception of the appropriate way to assess sex differences (Garcia-Sifuentes and Maney, 2021).”

• cites Garcia-Sifuentes and Maney, 2021 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

These regions have distinct roles in socio-sexual behavior in adulthood, often driven by distinct, separable cell type-specific and projection-specific mechanisms.

“These regions have distinct roles in socio-sexual behavior in adulthood as well, often driven by distinct, separable cell type-specific and projection-specific mechanisms (Unger et al., 2015; Wong et al., 2016; Ishii et al., 2017; Kohl et al., 2018).”

• cites Unger et al., 2015 sourcePartly supported

  The Discussion section (“Global versus modular control of complex social behaviors”; page unavailable) reports that aromatase-positive neurons in the medial amygdala regulate aggression but not sexual behavior, supporting a separable, cell-type-specific role. It does not establish the projection-specific mechanisms also attributed to this source. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites Wong et al., 2016 sourceSupported
• cites Ishii et al., 2017 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Isolation starting later in adolescence, from P28-70, produced hypersociability in both sexes in mice.

“In contrast, isolation starting later in adolescence, from P28–70, was shown to produce hypersociability in both sexes, although this study was conducted in mice (Rivera-Irizarry et al., 2020).”

• cites Rivera-Irizarry et al., 2020 sourceSupported

May combine two claims.

Play is itself a social behavior and involves the activity of many regions in the social circuitry, such as the medial amygdala, lateral septum, and hypothalamus.

“given play is itself a social behavior and involves the activity of many regions in the social circuitry, such as the medial amygdala, lateral septum, and hypothalamus (summarized in Siviy, 2016 and VanRyzin et al., 2020a).”

• cites Siviy, 2016 sourcePartly supported

  The Introduction describes social rough-and-tumble play in rats, while noting that human play can also be solitary. The Subcortical involvement section links play to activity in the medial amygdala and hypothalamus, and reports that a lateral septal infusion changes play in rats; it does not establish play-related neural activity in the lateral septum. The claim therefore overgeneralizes both the social nature of play and the evidence for activity in every listed region (page numbers unavailable). (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites VanRyzin et al., 2020aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

There was no effect of sex or housing condition on the discrimination ratio, indicating no difference in object memory.

“However, there was no effect of sex or housing condition on the discrimination ratio, indicating no difference in object memory.”

May combine two claims.

There was a significant reduction in the average mount rate in the SDB animals (p = 0.014), which was also trending in the LDB animals (p = 0.151).

“This resulted in a significant reduction in the average mount rate (the total number of mounts, intromissions, and ejaculations divided by the active time) in the SDB animals (p = 0.014; Figure 5C) which was also trending in the LDB animals (p = 0.151; Figure 5G).”

Probably not a substantial claim: may not pass S3 (load-bearing).

The sex by condition interaction on play did not reach statistical significance (p = 0.13).

“Although the sex × condition interaction did not reach statistical significance (p = 0.13)”

May combine two claims.

Even in naturally cycling conditions, there was no effect of play deprivation on either sexual receptivity or proceptivity.

“Even in naturally cycling conditions, we again observed no effect of play deprivation on either sexual receptivity or proceptivity (Figures 4C,D).”

May combine two claims.

There was a significant main effect of sex on distance traveled in the maze in both studies (SDB: p = 0.034; LDB: p = 0.005), with males exploring the maze significantly less than females.

“we observed a significant main effect of sex in the distance traveled in the maze in both studies (SDB: p = 0.034; LDB: p = 0.005; Figures 2B,D), with males exploring the maze significantly less than females.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Females across conditions were more locomotive on the open field test than males.

“As before, females across conditions were also more locomotive on this test than males.”

May combine two claims.

There were either significant or trending effects on the average number of mounts (SDB: p = 0.075; LDB: p = 0.029) and the average number of intromissions (SDB: p = 0.13; LDB: p = 0.016) in both the SDB and LDB animals, with BARR and ISO males exhibiting an often stepwise decrease in the numbers of both sexual behaviors compared to CTRL males.

“We observed either significant or trending effects on the average number of mounts (SDB: p = 0.075; LDB: p = 0.029; Figures 5A,E) and the average number of intromissions (SDB: p = 0.13; LDB: p = 0.016; Figures 5B,F) in both the SDB and LDB animals, with BARR and ISO males exhibiting an often stepwise decrease in the numbers of both sexual behaviors compared to CTRL males.”

May combine two claims.

There was no effect of sex or housing condition on center time in the open field in juvenile rats.

“We found no effect of sex or housing condition on center time in the open field (Figure 1B).”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

There was a small but significant sex difference in the LDB animals and a trending effect in the SDB animals (p = 0.007 and 0.097, respectively), whereby males spent significantly less time in the open arms of the maze.

“we observed a small but significant sex difference in the LDB animals with a trending effect in the SDB animals (p = 0.007 and 0.097, respectively) whereby males spent significantly less time in the open arms of the maze.”

May combine two claims.

Females prevented from playing as juveniles exhibited no effects on sexual behavior, sociability, or aggressiveness in adulthood.

“Males prevented from playing as juveniles exhibited decreased sexual behavior, hypersociability, and increased aggressiveness in adulthood, with no effects on these measures in females.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the LDB animals, there was a main effect of condition (p < 0.001) on distance traveled in the elevated plus maze.

“In the LDB animals, we also observed a main effect of condition (p < 0.001) on distance traveled.”

May combine two claims.

There was a significant main effect of sex and treatment on play data, with males of both housing conditions and ISO animals of both sexes playing significantly more than females and BARR animals, respectively.

“we detected a significant main effect of both sex (p = 0.036) and treatment (p = 0.026), with males of both housing conditions and ISO animals of both sexes playing significantly more than females and BARR animals, respectively.”

May combine two claims.

There was no effect of juvenile housing condition on female sexual behavior, with no differences in receptivity (lordosis quotient) or proceptivity (number of proceptive behaviors) across groups.

“We observed no effect of juvenile housing condition on female sexual behavior, as there were no differences in receptivity (lordosis quotient, Figure 4A) or proceptivity (number of proceptive behaviors, Figure 4B) across groups.”

May combine two claims.

Following a significant main effect of both sex (p < 0.001) and condition (p = 0.013) on gridline crossings, CTRL animals of both sexes were significantly less locomotive than BARR animals (p = 0.01), with a trending effect when compared to ISO animals (p = 0.117).

“Post hoc analysis following a significant main effect of both sex (p < 0.001) and condition (p = 0.013) on the number of gridline crossings indicated that CTRL animals of both sexes were significantly less locomotive than BARR animals (p = 0.01), with a trending effect when compared to ISO animals as well (p = 0.117).”

May combine two claims.

In the LDB animals, the distribution of ejaculators vs. non-ejaculators in BARR (p = 0.002) and ISO (p < 0.001) males significantly differed from the expected distribution, with only about 60% of animals ejaculating in one or both tests and about 40% being duds.

“However, the distribution of ejaculators vs. non-ejaculators in BARR (p = 0.002) and ISO (p < 0.001) males significantly differed from the expected distribution. In both groups, only ~60% of animals ejaculated in one or both tests, while ~40% were “duds”.”

May combine two claims.

There was a strong sex difference in the ratio of investigation duration, with males exhibiting ratios closer to 1, indicating less intact social recognition (SDB: p < 0.001; LDB: p < 0.001); this followed a sex difference in overall interaction times, whereby males spent much more time interacting with the stimulus animal across both trials than females did.

“Interestingly, we detected a strong sex difference in the ratio of investigation duration, with males exhibiting ratios closer to 1, indicating less intact social recognition (SDB: p < 0.001; LDB: p < 0.001; Figures 8B,D); this followed a sex difference we observed in the overall interaction times, whereby males spent much more time interacting with the stimulus animal across both trials than Fem”

May combine two claims.

There were trending effects of condition on the average number of keep downs (p = 0.189), lateral threats (p = 0.13), and upright postures (p = 0.088), but no difference in the number of clinch attacks.

“We detected trending effects of condition on the average number of keep downs (p = 0.189; Figure 9A), lateral threats (p = 0.13; Figure 9B), and upright postures (p = 0.088; Figure 9C), but no difference in the number of clinch attacks (Figure 9D).”

May combine two claims.

Using male data alone, datasets from both the SDB and LDB study indicated appropriateness for factor analysis, with an overall Kaiser-Meyer-Olkin MSA above 0.5 (SDB: MSA = 0.53; LDB: MSA = 0.53) and a significant p-value for Bartlett's test (SDB: p = 0.001; LDB: p < 0.001).

“Using male data alone, datasets from both the SDB and LDB study indicated appropriateness for factor analysis, with an overall Kaiser-Meyer-Olkin MSA above 0.5 (SDB: MSA = 0.53; LDB: MSA = 0.53) and a significant p-value for Bartlett’s test (SDB: p = 0.001; LDB: p < 0.001).”

May combine two claims.

Post hoc analyses indicated BARR males had a significantly higher positive score for the Socio-sexual Behavior factor than CTRL males in both studies (SDB: p = 0.019; LDB: p = 0.008), with trending effects compared to ISO males (SDB: p = 0.059; LDB: p = 0.147).

“Post hoc analyses indicated BARR males had a significantly higher positive score for this factor than CTRL males in both studies (SDB: p = 0.019; LDB: p = 0.008), and there were trending effects when compared to ISO males in both studies as well (SDB: p = 0.059; LDB: p = 0.147).”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the SDB study, the second factor (19.3% of total variance) contained positive loadings for discrimination ratio on the novel object recognition task and sex behavior mount rate.

“The second factor (19.3% of total variance) contained positive loadings for discrimination ratio on the novel object recognition task and sex behavior mount rate”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the LDB study, factor two (17.5% of total variance) contained strong positive loadings for distance traveled and open arm time on the elevated plus maze.

“while factor two (17.5% of total variance) contained strong positive loadings for distance traveled and open arm time on the elevated plus maze.”

May combine two claims.

Rats of both sexes were hyperactive shortly after play deprivation and displayed impairments in a test of empathy motivation when acutely prevented from playing.

“While rats of both sexes were hyperactive shortly after play deprivation and displayed impairments in a test of empathy motivation when acutely prevented from playing”

May combine two claims.

The performance of play-deprived animals improved to control levels by the second half of testing, with no effect of condition on this measure on days 7-12 of the assay.

“The performance of play-deprived animals improved to control levels by the second half of testing, as there was no effect of condition on this measure on days 7–12 of the assay (Figure 10D).”

• AssumptionRests on an assumption: The barrier (BARR) housing condition prevents social play while allowing other social interaction.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Factor analysis generated a three-factor solution for both the SDB and LDB datasets, and this three-factor solution was again identified after removing low-communality variables.

“which generated a three-factor solution for both the SDB and LDB datasets.”

• Also stated in: § Statistical analysis · plain

  “again identifying a three-factor solution for both datasets.”

May combine two claims.

In both the SDB and LDB studies, all six groups demonstrated social recognition, as their interaction time on the Test trial was significantly decreased compared to the Train trial, with the exception of the Male BARR group in the SDB study, which was trending (p = 0.085).

“In both the SDB and LDB studies, all six groups demonstrated social recognition (Figures 8A,C), as their interaction time on the Test trial was significantly decreased compared to that of the Train trial, with the exception of the Male BARR group in the SDB study, which was trending (p = 0.085).”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the LDB study, factor one (23.6% of total variance) contained strong positive loadings for center time and line crossings in the open field test, with negative loading for novel object discrimination ratio.

“Factor one (23.6% of total variance) contained strong positive loadings for center time and line crossings in the open field test, with negative loading for novel object discrimination ratio”

May combine two claims.

CTRL males exhibited significantly fewer total aggressive behaviors than ISO males (p = 0.005), with a trending effect when compared to BARR males (p = 0.056).

“Post hoc analysis indicated CTRL males exhibited significantly fewer total aggressive behaviors than ISO males (p = 0.005), with a trending effect when compared to BARR males (p = 0.056)”

May combine two claims.

In the LDB study, there was a small but significant (p = 0.003) sex difference in the percentage of time near the social box, with males showing increased social preference relative to females, but there was no effect of juvenile housing condition.

“However, while a small but significant (p = 0.003) sex difference in the percentage of time near the social box was detected in the LDB study (Figure 6C; ratio data shown in Figure 6D), with males showing increased social preference relative to females, there was no effect of juvenile housing condition.”

May combine two claims.

There was a sex difference in the prosocial helping task in both stages of testing, with males on average exhibiting significantly longer latencies to release their cagemates in the early stage (Days 1-6; p = 0.046) and a trending effect in the late stage (Days 7-12; p = 0.063).

“There was also a sex difference in this task in both stages of testing, with males on average exhibiting significantly longer latencies to release their cagemates in the early stage of testing (Days 1–6; p = 0.046) with a trending effect in the late stage of testing (Days 7–12; p = 0.063).”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the LDB study, three factors were sufficient to explain the data, accounting for 58% of the total variance.

“From this analysis, we again identified three factors to be sufficient to explain the data, accounting for 58% of the total variance (Figure 11C).”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the SDB study, three factors were sufficient to explain the data, accounting for 66.5% of the total variance.

“We identified three factors to be sufficient to explain the data, accounting for 66.5% of the total variance (Figure 11A).”

May combine two claims.

Around 40% of BARR and ISO males did not ejaculate in either test of copulatory behavior, a significant deviation from CTRL males (12.5%) and from the expected distribution of non-ejaculators (~10%).

“Around 40% of BARR and ISO males did not ejaculate in either test of copulatory behavior, a significant deviation from what was seen in CTRL males (12.5%) and from the expected distribution of non-ejaculators (~10%) based on decades of research on male rat sexual behavior (Dewsbury, 1972; Pattij et al., 2005; Portillo et al., 2006).”

• cites Dewsbury, 1972 sourceNot checked — no full text of the source
• cites Pattij et al., 2005 sourceNot checked — no full text of the source
• cites Portillo et al., 2006 sourceNot checked — no full text of the source

May combine two claims.

In both the SDB and LDB studies, all six groups demonstrated significant opposite-sex preference compared to chance (50%), with the exception of the two BARR groups in the LDB study, in which the one-sample t-test vs. chance was trending (Male BARR: p = 0.075; Female BARR: p = 0.148).

“In both the SDB and LDB studies, all six groups demonstrated significant opposite-sex preference as compared to chance (50%), with the exception of the two BARR groups in the LDB study, in which the one-sample t-test vs. chance was trending (Male BARR: p = 0.075; Female BARR: p = 0.148).”

May combine two claims.

No significant differences were detected as a result of condition on the percent of time spent near the opposite-sex stimulus box, indicating sex preference in adulthood is unaffected by juvenile play deprivation.

“However, no significant differences were detected as a result of condition on the percent of time spent near the opposite-sex stimulus box (Figures 7A,C), indicating sex preference in adulthood is unaffected by juvenile play deprivation.”

May combine two claims.

There were no sex differences on the percent time near the opposite-sex stimulus box in either the SDB or LDB animals, but a main effect of sex was detected when considering the ratio of time spent near the opposite sex compared to the same-sex stimulus box in the LDB animals but not the SDB animals, with males exhibiting stronger opposite-sex preference than females.

“While there were no sex differences on this measure in either the SDB or LDB animals, a main effect of sex was detected when considering the data as a ratio of the time spent near the opposite sex compared to the same-sex stimulus box in the LDB animals (Figure 7D) but not the SDB animals (Figure 7B), with males exhibiting stronger opposite-sex preference than females.”

May combine two claims.

The additional non-play social experience provided by the BARR vs. the ISO housing condition is sufficient to decrease play motivation in females but not males.

“In our initial studies, we found that the additional non-play social experience provided by the BARR vs. the ISO housing condition is sufficient to decrease play motivation in females but not males (Figure 1C)”

May combine two claims.

Play deprivation had no effect on anxiety-like behavior, object memory, sex preference, and social recognition in both sexes, and on sex behavior and social preference in females.

“Our findings in which we observed play deprivation had no effect—on anxiety-like behavior, object memory, sex preference, and social recognition in both sexes and on sex behavior and social preference in females”

May combine two claims.

Juvenile play deprivation increases aggressive behavior in adult males, not decreases as a straightforward interpretation of the play-as-practice theory would predict.

“We here provide further evidence against the play-as-practice theory, as we demonstrate that juvenile play deprivation increases aggressive behavior in adult males, not decreases as a straightforward interpretation of the theory would predict.”

May combine two claims.

The hypersocial phenotype was seen across multiple SDB cohorts, with a substantial effect size (Cohen's d ranging between 1.9 and 2.9 for all pairwise comparisons between Male BARR and the other groups for percent of time near the social box).

“This hypersocial phenotype was seen across multiple SDB cohorts, and the effect size was substantial (Cohen’s d ranging between 1.9 and 2.9 for all pairwise comparisons between Male BARR and the other groups for percent of time near the social box; Figure 6A).”

May combine two claims.

Males generally performed worse than females in the empathy assay, exhibiting a significantly higher latency to release their cagemate on average in the first half of testing.

“We also observed a sex difference in this assay: males generally performed worse than females, as they exhibited a significantly higher latency to release their cagemate on average in the first half of testing.”

Probably not a substantial claim: may not pass S4 (based).

The vast majority of studies on effects of juvenile social isolation were conducted in one sex only.

“the vast majority of these studies were conducted in one sex only”

Classified as probably not a substantial claim. May combine two claims.

There are known sex differences in play's expression: across nearly all species that play, males play more frequently and intensely than females, and there are qualitative sex differences in play patterns.

“there are known sex differences in play’s expression: across nearly all species that play, males play more frequently and intensely than females, and there are qualitative sex differences in play patterns.”

• cites VanRyzin et al., 2020aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Pellis and Pellis, 1990, 1997Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Social play is a dynamic and rewarding behavior abundantly expressed by most mammals during the juvenile period.

“Social play is a dynamic and rewarding behavior abundantly expressed by most mammals during the juvenile period.”

• cites Pellis and Pellis, 2009Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Classified as probably not a substantial claim. May combine two claims.

Participating in play is essential to appropriate behavior and reproductive success in adulthood.

“While its exact function is debated, various rodent studies on the effects of juvenile social isolation suggest that participating in play is essential to appropriate behavior and reproductive success in adulthood.”

• cites Hol et al., 1999 sourceNot checked — no full text of the source
• cites Gerall et al., 1967 sourceNot checked — no full text of the source
• cites Cooke et al., 2000 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The position of objects within the arena and the order of object exposure was counterbalanced across groups.

“The position of objects within the arena and the order of object exposure was counterbalanced across groups.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Juvenile social isolation in rats increases anxiety- and depression-like behavior.

“increases anxiety- and depression-like behavior (Parker and Morinan, 1986; Wright et al., 1991; Arakawa, 2003; Leussis and Andersen, 2008; Lukkes et al., 2009; Cuesta et al., 2020)”

• cites Parker and Morinan, 1986 sourceNot checked — no full text of the source
• cites Wright et al., 1991 sourceNot checked — no full text of the source
• cites Arakawa, 2003 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In many studies, animals were isolated through adulthood, when testing was conducted; it is unclear whether there may be an effect of acute isolation on observed phenotypes.

“Second, in many of these studies, animals were isolated through adulthood, when testing was conducted; as such, it is also unclear whether and to what extent there may be an effect of acute isolation on the observed phenotypes.”

Probably not a substantial claim: may not pass S3 (load-bearing).

All behavioral tests were performed and scored offline by an experimenter blind to condition (at all times) and sex (when appropriate).

“Unless stated otherwise, all behavioral tests were performed and scored offline by an experimenter blind to condition (at all times) and sex (when appropriate).”

Probably not a substantial claim: may not pass S3 (load-bearing).

A control experiment was independently conducted for social recognition, with a novel stimulus rat in both Train and Test trials, to control for effects of a second interaction trial unrelated to recognition.

“Separately, a control experiment was independently conducted which followed the same procedure; however, a novel stimulus rat was placed in the cage with the test rat in both the Train trial and the Test trial, to control for any effects of a second interaction trial in general, unrelated to recognition of the stimulus animal or the lack thereof.”

May combine two claims.

The increased social interaction allowed by the BARR housing condition is sufficient to reduce play motivation in females but not males.

“This suggests that the increased social interaction allowed by the BARR housing condition is sufficient to reduce play motivation in females but not males, an unexpected finding speaking to the differential role that play may serve in females compared to males.”

• AssumptionRests on an assumption: The barrier (BARR) housing condition prevents social play while allowing other social interaction.

Probably not a substantial claim: may not pass S3 (load-bearing).

The effect of housing condition on play seems to be driven more strongly in females than in males.

“However, this effect of the condition seems to be driven more strongly in females than in males.”

Classified as probably not a substantial claim.

The initial studies provide intriguing evidence in support of the idea that play may serve different purposes across the sexes.

“and provides intriguing evidence in support of the idea that play may serve different purposes across the sexes.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Condition groups and sexes were balanced across multiple litters.

“Both male and female pups were used, with condition groups and sexes balanced across multiple litters.”

Classified as probably not a substantial claim.

The majority of these studies were conducted in only one sex-typically male subjects-preventing assessment of sex differences in identified impairments.

“Finally, and most notably, the majority of these studies were conducted in only one sex—typically, male subjects—thereby preventing the ability to assess whether there are sex differences in the identified impairments.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The position of the social chamber and the empty chamber within the arena was counterbalanced across groups.

“The position of the social chamber and the empty chamber within the arena was counterbalanced across groups.”

May combine two claims.

The perforated Plexiglass cage divider prevents play while still allowing for other forms of social interaction in the visual, auditory, olfactory, and tactile domain.

“Improving upon the previous methodology, this manipulation prevents play while still allowing for other forms of social interaction in the visual, auditory, olfactory, and tactile domain.”

Probably not a substantial claim: may not pass S2 (checkable).

Use of total isolation to prevent interactions with other juveniles limits understanding of the importance of play.

“Further limiting our understanding of the importance of play is the use of total isolation to prevent interactions with other juveniles.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The position of the chamber containing the male stimulus animal and the chamber containing the female stimulus animal within the arena was counterbalanced across groups.

“The position of the chamber containing the male stimulus animal and the chamber containing the female stimulus animal within the arena was counterbalanced across groups.”

May combine two claims.

The modified housing used to prevent play does not in itself increase anxiety-like behavior or impair the ability to play if given the opportunity.

“Overall, these initial studies indicate that the modified housing used to prevent play does not in itself increase anxiety-like behavior or impair the ability to play if given the opportunity”

• AssumptionRests on an assumption: The barrier (BARR) housing condition prevents social play while allowing other social interaction.

Probably not a substantial claim: may not pass S3 (load-bearing).

The SDB third factor was titled "Socio-sexual behavior" because it contained two tests within the socio-sexual domain.

“two tests within the socio-sexual domain (hence titled “Socio-sexual behavior”).”

May combine two claims.

P45 is an age when rats of both sexes have typically entered puberty, at which point playfulness dramatically decreases.

“an age when rats of both sexes have typically entered puberty, at which point playfulness dramatically decreases (Meaney and Stewart, 1981; Panksepp, 1981).”

• cites Meaney and Stewart, 1981 sourceNot checked — no full text of the source
• cites Panksepp, 1981 sourceNot checked — no full text of the source

May combine two claims.

The increased social preference in male BARR animals appeared to be a true difference in sociability not affected by differences in overall exploration time, as there was no effect of condition on the time spent near either stimulus box.

“This appeared to be a true difference in sociability not affected by differences in overall exploration time, as there was no effect of condition on the time spent near either stimulus box (Supplementary Figure 1A).”

Probably not a substantial claim: may not pass S3 (load-bearing).

The SDB first factor was interpreted as reflecting a latent anxiety-like phenotype and renamed "Anxiety".

“As these enriched behaviors generally reflected measures of a latent anxiety-like phenotype, we renamed it accordingly (“Anxiety”).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Around 10% of all sexually mature male rats are duds (sexually sluggish), meaning that they do not ejaculate in the course of a 20-30 min assay with a sexually receptive female.

“It is well known in the field of rodent sexual behavior that around 10% of all sexually mature male rats will be “duds” (otherwise known as “sexually sluggish”), meaning that they do not ejaculate in the course of a 20–30 min assay with a sexually receptive female (Dewsbury, 1972; Pattij et al., 2005; Portillo et al., 2006).”

• cites Dewsbury, 1972 sourceNot checked — no full text of the source
• cites Pattij et al., 2005 sourceNot checked — no full text of the source
• cites Portillo et al., 2006 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The LDB first two factors were renamed "Anxiety I" and "Anxiety II".

“As such, we renamed the factors as “Anxiety I” and “Anxiety II”, respectively.”

May combine two claims. The quote only partly states this claim.

The effects of juvenile play deprivation are complex and pervasive, seen weeks to months after all animals were returned to group housing, and impact reproductively critical behaviors.

“These effects are complex and pervasive, seen weeks to months after all animals were returned to group housing, and impact reproductively critical behaviors.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The SDB second factor was interpreted as reflecting recognition of the salience of a given stimulus and renamed "Salience".

“both phenotypes that require recognition of the salience of a given stimulus; thus, we renamed the factor as such (“Salience”).”

May combine two claims.

Juvenile play deprivation impairs both the number/rate of sexual behaviors (SDB and LDB) and the proportion of animals which successfully ejaculate (LDB) in adult males.

“Together, these studies indicate that juvenile play deprivation impairs both the number/rate of sexual behaviors (SDB and LDB) and the proportion of animals which successfully ejaculate (LDB) in adult males, a notable finding given the paramount importance sexual behavior plays in reproductive fitness.”

• AssumptionRests on an assumption: The barrier (BARR) housing condition prevents social play while allowing other social interaction.

May combine two claims.

The reduction in mount rate was seen in both BARR and ISO males, indicating that the lack of play, not the lack of social interaction writ large, was the critical driver of this impairment.

“This was seen in both BARR and ISO males, indicating that the lack of play, not the lack of social interaction writ large, was the critical driver of this impairment.”

May combine two claims.

The impairment in male copulatory behavior did not seem to represent a simple delay in learning, but rather a persistent reduction in the rate of copulatory behavior, evident across both successive tests.

“Moreover, this impairment did not seem to represent a simple delay in the learning process, but rather a persistent reduction in the rate of copulatory behavior; while we present the data here as an average, the deficit in BARR and ISO males was evident across both successive tests.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The LDB third factor was titled "Socio-sexual behavior".

“hence titled “Socio-sexual behavior””

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Perhaps in females, the significance of play is more so the social experience in general, and less so the experience of play itself.

“Perhaps in females, the significance of play is more so the social experience in general, and less so the experience of play itself.”

May combine two claims.

It appears little social experience during the juvenile window is necessary for appropriate social development in females, given few impairments were observed following even full social isolation.

“Even then, it appears little social experience during the juvenile window is necessary for appropriate social development in females, given we observed few impairments following even full social isolation.”

Probably not a substantial claim: may not pass S3 (load-bearing).

BARR animals may perform worse on the empathy test due to a deficit in their perception of and/or responsiveness to the social signals generated by their distressed cagemate.

“In this view, BARR animals may perform worse on the empathy test due to a deficit in their perception of and/or responsiveness to the social signals generated by their distressed cagemate.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The "play-as-practice" theory argues that the individual behaviors constituting social play resemble adult agonistic behaviors because play serves as practice for later-life aggressive encounters.

“One of many theories regarding the function of social play is the “play-as-practice” theory, which argues that the individual behaviors constituting social play (e.g., pounces, pins, and boxing behaviors in rats) resemble adult agonistic behaviors for a reason: because play serves as practice for later-life aggressive encounters (Fagen, 1981; Smith, 1997).”

• cites Fagen, 1981 sourceNot checked — no full text of the source
• cites Smith, 1997 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Reciprocity is a fundamental feature of social play.

“This reciprocity—necessitating monitoring one’s own actions and those of a partner, recognizing social signals indicating the partner’s responses and intentions, and adjusting one’s actions appropriately to maintain the back-and-forth of the play bout—is a fundamental feature of social play (Pellis and Pellis, 2017)”

• cites Pellis and Pellis, 2017Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

It is possible that no effect on sociability was observed in the LDB study because the play deprivation spanned across the two sensitive windows (from P21-45), canceling out any effects.

“In this view, it is possible we observed no effect on sociability in the LDB study as the play deprivation spanned across those windows (from P21–45), canceling out any effects.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Play experience may be fundamental to the developmental firing and wiring of individual cells and projections that establishes appropriate adult circuit organization.

“play experience may be fundamental to the developmental firing and wiring of individual cells and projections that establishes appropriate adult circuit organization.”

May combine two claims.

Social isolation from P22-28, but not P29-35, decreases sociability in adulthood in male rats.

“Work from Hol et al. (1999) demonstrated that social isolation from P22–28, but not P29–35, decreases sociability in adulthood in male rats.”

• cites Hol et al. (1999) sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

This finding may serve as another example of the concept that play aids in developing the ability to appropriately sense and respond to social signals.

“This finding may serve as another example of the concept that play aids in developing the ability to appropriately sense and respond to social signals.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Long-term post-weaning social isolation has been shown to induce qualitative differences in the attack patterns of male rats.

“and long-term post-weaning social isolation has been shown to induce qualitative differences in the attack patterns of male rats (Toth et al., 2011).”

• cites Toth et al., 2011 sourceNot checked — no full text of the source

May combine two claims.

The effects of play deprivation preferentially center around socio-sexual behaviors in adulthood, supported by factor analyses identifying socio-sexual behavior factors that significantly differed in control and play-deprived males.

“The effects of play deprivation (and therefore, the importance of play itself) seem to preferentially center around socio-sexual behaviors in adulthood, a concept further supported by our factor analyses, which in an independent and unbiased manner identified factors in both the SDB and LDB studies that represent socio-sexual behavior and significantly differed in control and play-deprived males.”

Classified as probably not a substantial claim.

Our results would argue that boys may be more vulnerable to a reduction in access to play than girls.

“Our results would argue that boys may be more vulnerable to a reduction in access to play than girls.”

• AssumptionRests on an assumption: Social play is remarkably similar across the many mammalian species in which it is expressed and has strong face validity in humans.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The impairment in the prosocial motivation task may have improved over time due to the increased social experience afforded as part of the test, or because animals had sufficient experience with the paradigm by the latter half of testing.

“This impairment may have improved over time due to the increased social experience afforded as part of the test (while animals were allowed only 10 s to interact with their cagemate following release from the confinement box, this social experience may have accumulated over time), or because animals had sufficient experience with the paradigm by the latter half of testing such that it allowed BARR”

Probably not a substantial claim: may not pass S3 (load-bearing).

The differential effect on social preference in the SDB compared to the LDB study may be due to an as-yet-unidentified sensitive period for social development around the time of weaning.

“This differential effect in the SDB compared to the LDB study may be due to an as-yet-unidentified sensitive period for social development around the time of weaning.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

This sex difference may speak to the heightened importance of play experience in males compared to females, given even at baseline males are less successful on this socially-driven task.

“This too may speak to the heightened importance of play experience in males compared to females, given even at baseline males are less successful on this socially-driven task.”

Classified as probably not a substantial claim.

Sex was statistically tested as a variable, calling a finding a "sex difference" if and only if a significant main effect of sex or a significant interaction was detected.

“We statistically tested sex as a variable, calling a finding a “sex difference” if and only if we detected a significant main effect of sex or a significant interaction.”

Classified as probably not a substantial claim. May combine two claims.

When possible, males and females were included in all experiments, all of which were adequately powered to detect sex differences if they were present.

“When possible (i.e., in assays that are not only applicable to animals of one sex), males and females were included in all experiments, all of which were adequately powered to detect sex differences if they were present.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The BARR manipulation improves upon previous methodology in that it prevents play while allowing for other forms of social interaction.

“While our BARR manipulation improves upon previous methodology in that it prevents play while allowing for other forms of social interaction, there are nonetheless limitations.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

BARR animals are also deprived of other tactile non-play social interactions such as social grooming, and other variables such as the difference in physical space allowed by the BARR vs. CTRL and ISO conditions may affect development.

“BARR animals are also deprived of other tactile non-play social interactions such as social grooming, and there may be other variables such as the difference in physical space allowed by the BARR vs. CTRL and ISO conditions that may affect development.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The maturation of these cell subtypes and/or projections may be modulated in an experience-dependent (and potentially sex-dependent) manner based on playfulness.

“The maturation of these cell subtypes and/or projections, then, may be modulated in an experience-dependent (and, potentially, sex-dependent) manner based on playfulness.”

May combine two claims.

Animals deprived of play may lack this experience, thereby hindering their ability to appropriately recognize and/or respond to social signals to de-escalate an agonistic encounter, resulting in increased aggression.

“Animals deprived of play may lack this experience, thereby hindering their ability to appropriately recognize and/or respond to social signals to de-escalate an agonistic encounter, resulting in increased aggression as we observed.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

The female resilience may not be true for all traits, or there may be latent differences in assessed traits not detectable by the paradigms used to evaluate them.

“this may not be true for all traits, or there may be latent differences in our assessed traits not detectable by the paradigms we used to evaluate them.”

Probably not a substantial claim: may not pass S3 (load-bearing).

It is possible that the additional stress caused by full isolation may alter the direction and magnitude of these effects.

“It is also possible that the additional stress caused by full isolation may alter the direction and magnitude of these effects, given ours were seen only in BARR, but not ISO, males.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The play-as-practice theory has received criticism because there are key differences in the microstructure of juvenile play-fighting and adult aggressive behaviors.

“This theory has received criticism for various reasons, primarily that there are several key differences in the microstructure of juvenile play-fighting and adult aggressive behaviors, thus hindering play’s applicability as a means of physical “practice” (Pellis and Pellis, 1987).”

• cites Pellis and Pellis, 1987 sourceNot checked — no full text of the source

May combine two claims.

Play may serve to provide experience in social skills, allowing for the maturation of brain circuitry to the same effect.

“so play may serve to provide experience in these social skills, allowing for the maturation of brain circuitry to the same effect.”