Hormonal mechanisms of cooperative behaviour

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

Of the many different hormones present in vertebrates, three groups have received most attention in terms of their role in the expression of social behaviour: sex hormones, stress hormones and neuropeptides from the vasopressin/oxytocin family.

“Of the many different hormones present in vertebrates, there are three groups that have received most attention in terms of their role in the expression of social behaviour: sex hormones, stress hormones and neuropeptides from the vasopressin (AVP)/oxytocin (OT) family”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Social behaviour is naturally related with reproduction and to responses to emergencies or challenges.

“social behaviour is naturally related with reproduction and to responses to emergencies or challenges”

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

Testosterone plays a pivotal role in the regulation of morphology, physiology and behaviour of male vertebrates.

“testosterone, the principal steroid secreted by most vertebrate testes, which plays a pivotal role in the regulation of morphology, physiology and behaviour of male vertebrates”

• cites Wingfield et al. 2006Not checked yet

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

Both sex and stress hormones are organized in specific neuroendocrine axes, the HPG and HPA axes, both of which are organized in a hierarchical fashion.

“Both sex and stress hormones are organized in specific neuroendocrine axes, the hypothalamicpituitary-gonadal (HPG) and the hypothalamicpituitary-adrenal (HPA) axes, both of which are organized in a hierarchical fashion.”

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

Functional effects of hormones are rapid and short-lived; structural effects are slow and long-lasting.

“Functional effects are rapid and short-lived and can either result from a direct effect of hormones on neural excitability and neurotransmission”

• Also stated in: § 2. A PRIMER TO THE NEUROENDOCRINE REGULATION OF SOCIAL BEHAVIOUR (a) Hormonal modulation of social behaviour · plain

  “Structural effects are slow and long-lasting”

• cites Remage-Healey & Bass 2006aNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

These behavioural traits are also likely to determine the tendency of an individual to show cooperative behaviour.

“These behavioural traits are also likely to determine the tendency of an individual to show cooperative behaviour.”

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

At the top of the HPG and HPA hierarchies are hypothalamic peptides that control the synthesis and release of specific tropic hormones in the anterior pituitary, which in turn regulate production of specific steroids in the gonads and adrenals.

“At the top of the hierarchy are the hypothalamic peptides, i.e. gonadotropin-releasing hormone in the HPG and corticotropin-releasing hormone in the HPA, which control the synthesis and release of specific tropic hormones in the anterior pituitary”

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

Organizational effects of hormones are usually only effective at an early stage of life within strict time windows and are expected to last for the entire lifespan of the individual.

“These latter effects are usually only effective at an early stage of life within strict time windows termed sensitive or critical periods, and are expected to last for the entire lifespan of the individual.”

Classified as probably not a substantial claim.

Behaviour is influenced by hormones.

“Countless studies have convincingly demonstrated that behaviour is influenced by hormones.”

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

The posterior pituitary receives neural projections from hypothalamic neurons, which release neurohormones into the bloodstream.

“the posterior pituitary receives neural projections from the hypothalamic neurons, which end in a capillary network, where the neurohormones produced by these neurons are released into the bloodstream.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Hormones have both activational and organizational influence on general social behaviour.

“Hormones are likely to affect levels of helping in various ways as they have both activational and organizational influence on general social behaviour.”

May combine two claims.

A single hormone may have effects on many different aspects of behaviour, which may depend on social context and the life-history stage.

“A single hormone may have effects on many different aspects of behaviour, which may depend on social context and the life-history stage”

• cites Wingfield 2008Not checked yet

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

A hormone may have pleiotropic effects by affecting many different traits at the same time, thereby acting as the proximate mediator of functional trade-offs.

“a hormone may also have pleiotropic effects by affecting many different traits at the same time, thereby acting as the proximate mediator of functional trade-offs”

• cites Lessells 2008Not checked yet

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May combine two claims.

The modulatory action of hormones on the nervous system can occur at a functional level, by changing the activity of a given neural circuit, or at a structural level, by changing the architecture and/or connectivity of different nodes of the neural circuit.

“The modulatory action of hormones on the nervous system can occur at a functional level, by changing the activity of a given neural circuit, or at a structural level, by changing the architecture and/or connectivity of different nodes of the neural circuit.”

May combine two claims.

Hormones may modulate the expression of behaviour, but are not causes of behaviour.

“Hormones may modulate the expression of behaviour, but are not causes of behaviour.”

• cites Nelson 2005Not checked yet

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• cites Oliveira 2005Not checked yet

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May combine two claims.

Androgens are behavioural facilitators by acting as modulators of neural pathways of social behaviour, while their concentrations may respond to social circumstances.

“androgens are behavioural facilitators by acting as modulators of neural pathways of social behaviour, while in turn their concentrations may respond to social circumstances”

• cites Wingfield et al. 1990Not checked yet

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• cites Oliveira 2004Not checked yet

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• cites Goymann et al. 2007Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

To ensure successful operation within the group, individual recognition and cooperation between individuals (e.g. pair partners or similar social alliances) may be essential.

“To ensure successful operation within the group, individual recognition and cooperation between individuals (e.g.pair partners or similar social alliances) may be essential.”

May combine two claims.

Steroid and neuropeptide receptors are present in different nodes of the social behaviour neural network, suggesting that plasticity in social behaviour is likely to be modulated by these hormones.

“Steroid and neuropeptide (AVP, OT and their nonmammalian homologues) receptors are present in different nodes of this network, suggesting that plasticity in social behaviour is likely to be modulated by these hormones”

• cites Goodson 2005Not checked yet

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May combine two claims.

Cleaner fish (Labroides dimidiatus) are able to distinguish between familiar and unfamiliar clients from the same client species, and prefer to interact with familiar ones.

“cleaner fish (Labroides dimidiatus) are able to distinguish between familiar and unfamiliar clients from the same client species, and prefer to interact with familiar ones”

• cites Tebbich et al. 2002Not checked yet

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Probably not a substantial claim: may not pass S1 (asserted). May combine two claims.

According to this hypothesis, OT acting on hindbrain parasympathetic systems should stimulate prosocial behaviour, whereas AVP acting on sympathetic pathways should be associated with social withdrawal and/or aggression.

“According to this hypothesis, OT acting on hindbrain parasympathetic systems should stimulate prosocial behaviour, whereas AVP acting on sympathetic pathways should be associated with social withdrawal and/or aggression.”

• cites Porges 2001Not checked yet

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Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Proximate mechanisms are required that make an individual tolerate the presence of conspecifics, coordinate its actions to produce behaviour that reduces immediate pay-offs, recognize partners and assess their behaviour, and choose appropriate responses from the available behavioural repertoire.

“proximate mechanisms are required that make an individual tolerate the presence of conspecifics, coordinate its actions to produce behaviour that reduces immediate pay-offs, recognize partners and assess their behaviour, and choose the appropriate responses from the available behavioural repertoire.”

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

A first condition for the occurrence of cooperative behaviour is that individuals show a predisposition to approach conspecifics or other potential partners, and tolerate their presence.

“A first condition for the occurrence of cooperative behaviour is that individuals show a predisposition to approach conspecifics or other potential partners, and tolerate their presence.”

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

This social behaviour neural network is seen as the core of the social brain but it is not its whole, since other brain areas are relevant for social behaviour.

“This network is seen as the core of the social brain but it is certainly not its whole, since there are other brain areas that are quite relevant for social behaviour”

May combine two claims.

Intranasal administration of OT improves the capacity to recognize faces but has no effect on memorization of non-social stimuli in humans.

“Intranasal administration of OT improves the capacity to recognize faces, but has no effect on the memorization of non-social stimuli (Rimmele et al. 2009).”

• cites Rimmele et al. 2009Not checked yet

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May combine two claims.

OT-knockout mice fail to show behaviours indicating recognition of familiar individuals despite normal olfaction and no generalized deficits in learning and memory.

“OT-knockout mice are not olfactory impaired and show no generalized deficits in learning and memory, and yet they fail to show behaviours which would indicate that they recognize familiar individuals, even after repeated encounters (Ferguson et al. 2000).”

• cites Ferguson et al. 2000Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Social animals may take advantage of living in groups which are organized in complex social networks of related and unrelated individuals.

“Social animals may take advantage of living in groups which are organized in complex social networks of related and unrelated individuals.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Bonding mechanisms may be necessary to avoid aggression against partners.

“Bonding mechanisms may be necessary to avoid aggression against partners.”

Classified as probably not a substantial claim.

The tendency to approach a partner in a cooperative context must overcome the tendency for social withdrawal.

“Therefore, the tendency to approach a partner in a cooperative context overcome the tendency for social withdrawal.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Bonding may be crucial for any individual's willingness to invest: by creating affection towards another individual, bonding may help to overcome the problem of objective reduction in immediate gains through cooperative behaviour.

“Bonding may also be crucial for any individual's willingness to invest: by creating affection towards another individual, bonding may help to overcome the problem of objective reduction in immediate gains through cooperative behaviour.”

May combine two claims.

In the goldfish (Carassius auratus), central infusions of AVT inhibit social approach, whereas the administration of an AVT antagonist or of IT stimulated social approach.

“in the goldfish (Carassius auratus), central infusions of AVT inhibit social approach, whereas the administration of an AVT antagonist or of IT stimulated social approach”

• cites Thompson & Walton 2004Not checked yet

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May combine two claims.

Social recognition is necessary to distinguish between cooperators and cheaters or between partners and opponents.

“Social recognition is necessary to distinguish between cooperators and cheaters or between partners and opponents.”

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

Simple (i.e. genetically coded) solutions may exist, for example if partners are sessile.

“Simple (i.e.genetically coded) solutions may exist, for example if partners are sessile”

• cites Brosnan et al. 2010Not checked yet

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May combine two claims.

The two cell types have different projections associated with differential function: magnocellular cells project to the posterior pituitary for peripheral effects, whereas parvocellular cells project to limbic areas for central effects on the brain.

“the OT and AVP hypothalamic magnocellular cells project to the posterior pituitary and these pathways are responsible for peripheral systemic effects of these neuropeptides (e.g.AVP: anti-diuretic; OT: parturition and lactation); whereas the AVP and OT parvocellular cells project to limbic areas, including several of the nodes of the social behaviour neural network described above, and this system”

• cites De Vries & Panzica 2006Not checked yet

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• cites Caldwell 2008bNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In many vertebrate animals, the brain mechanisms described above allow individuals to more flexibly respond to environmental stimuli.

“However, in many vertebrate animals, the brain mechanisms described above allow individuals to more flexibly respond to environmental stimuli.”

May combine two claims.

AVP is involved in the formation of social memories, as shown by AVP-deficient Brattelboro rats having totally disrupted social recognition.

“The involvement of AVP in the formation of social memories was originally illustrated by the finding of the AVP-deficient Brattelboro rat, which has a totally disrupted social recognition (Feifel et al. 2009).”

• cites Feifel et al. 2009Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Individual recognition or recognition of different classes of social partners is both the basis and the consequence of interactions with others, and requires consolidation of memory of past interactions and outcomes.

“Individual recognition or recognition of different classes of social partners (e.g.cooperators versus noncooperators) is both the basis and the consequence of interactions with others, and requires consolidation of memory of past interactions and outcomes.”

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

There is a continuum from neurocrine to endocrine communication, and hormonal and neural mechanisms are interconnected with multiple reciprocal effects.

“In short, there is a continuum from neurocrine to endocrine communication, and hormonal and neural mechanisms are interconnected with multiple reciprocal effects.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Both the perception of the partner's effort and the critical threshold that may cause a switch in behavioural responses can be affected by hormones.

“Both the perception of the partner's effort and the critical threshold that may cause a switch in behavioural responses can be affected by hormones.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

Considering the vast diversity of examples for cooperation, there likely exists an equal diversity of mechanisms that regulate cooperation.

“Considering the vast diversity of examples for cooperation, there likely exists an equal diversity of mechanisms that regulate cooperation.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Individuals may adjust their behaviour depending on how a partner has behaved in the past, especially if these previous interactions were risky or involved cheating.

“Individuals may adjust their behaviour depending on how a partner has behaved in the past, especially if these previous interactions were risky or involved cheating.”

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

The biological market paradigm is linked to communication and negotiation.

“This biological market paradigm (Noe ¨2001) is linked to communication and negotiation.”

• cites Noe ¨2001Not checked yet

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May combine two claims.

Bystanders may gain information about interacting partners and may adjust their future behaviour with these partners depending on their observations.

“Bystanders may gain information about interacting partners and may adjust their future behaviour with these partners depending on their observations.”

May combine two claims.

A set of brain areas in the basal forebrain and midbrain are involved in the regulation of multiple forms of social behaviour and have bidirectional connections between each pair.

“A set of brain areas in the basal forebrain and midbrain have been identified as being involved in the regulation of multiple forms of social behaviour (aggression, affiliation, bonding, parental behaviour, social stress) and to have bidirectional connections between each pair”

• cites Newman 1999Not checked yet

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• cites Goodson 2005Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Neurotransmitters and neuromodulators are also known to modulate behavioural expression.

“Neurotransmitters and neuromodulators are also known to modulate behavioural expression.”

Probably not a substantial claim: may not pass S1 (asserted).

It has been hypothesized that AVP and OT may influence basic emotional mechanisms that regulate social approach and social aversion.

“It has been hypothesized that AVP and OT may influence basic emotional mechanisms that regulate social approach and social aversion”

• cites Porges 2001Not checked yet

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Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Hormones are known to affect and be affected by components of cooperative behaviour.

“Hormones are known to affect and be affected by the following components of cooperative behaviour.”

May combine two claims.

Newman originally proposed the existence of this social behaviour neural network in mammals, and Goodson confirmed its presence across different vertebrate classes and identified putative homologous areas.

“Newman (1999) originally proposed the existence of this social behaviour neural network in mammals, and Goodson (2005) confirmed its presence across different vertebrate classes and identified the putative homologous areas for each node in the different classes and/or taxa.”

• cites Newman 1999Not checked yet

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• cites Goodson 2005Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Steroid hormones modulate the synthesis of neuropeptides and their receptors and therefore may also exert their effects indirectly through the AVP/OT neuromodulatory system.

“steroid hormones are also known to modulate the synthesis of neuropeptides and their receptors and therefore may also exert their effects indirectly through the AVP/OT neuromodulatory system.”

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

All of these hormonal effects may occur in different compartments of the neural circuits underlying behaviour, thereby affecting the perception, the valence and the salience of social interactions.

“All of these may occur in different compartments of the neural circuits underlying behaviour (input, central processing, output), therefore affecting the perception, the valence and the salience of social interactions.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Flexible behavioural responses require neural plasticity, which can be achieved by the chemical modulation of neural circuits at various levels.

“flexible behavioural responses require neural plasticity, which can be achieved by the chemical modulation of neural circuits at various levels.”

May combine two claims.

OT is important for mate recognition and pair bond formation in monogamous voles.

“In monogamous voles, OT is important for mate recognition and pair bond formation (Young & Wang 2004).”

• cites Young & Wang 2004Not checked yet

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

The hippocampus is a brain area involved in relational memory processing and episodic memory.

“a brain area involved in relational memory processing and episodic memory (Squire 1992;Eichenbaum et al. 1999)”

• cites Squire 1992Not checked yet

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• cites Eichenbaum et al. 1999Not checked yet

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May combine two claims.

OT increases trust by reducing amygdala activation and concomitantly anxiety states associated with the possibility of non-reciprocation.

“Thus, OT seems to increase trust by reducing amygdala activation and concomitantly anxiety states associated with the possibility of non-reciprocation.”

May combine two claims.

The ability to remember specific aspects of past social encounters (episodic memory) would allow individuals to reciprocate cooperative behaviour and to punish non-cooperators.

“the ability to remember specific aspects of past social encounters, such as a relative place in time and space, associated emotions and other contextual knowledge (i.e.episodic memory) would allow individuals to reciprocate cooperative behaviour and to punish non-cooperators.”

May combine two claims.

Species with different life histories will differ both with respect to organizational and activational effects of hormones, which may also promote or hinder the expression of cooperative behaviour.

“Third, species with different life histories will differ both with respect to organizational and activational effects of hormones, which may also promote or hinder the expression of cooperative behaviour.”

May combine two claims.

AVP V1b receptor knockout mice display impaired social memory, despite having normal olfactory ability and other memory functions (e.g. spatial memory).

“AVP V1b receptor knockout mice also display impaired social memory, despite having normal olfactory ability and other memory functions (e.g.spatial memory; Wersinger et al. 2004).”

• cites Wersinger et al. 2004Not checked yet

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

Hormones may affect the basic mood of an individual, which in turn may influence neuronal decisions.

“Hormones may affect the basic mood of an individual, which in turn may influence neuronal decisions.”

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

The existence of episodic memory in animals is still a matter of debate.

“The existence of episodic memory in animals is still a matter of debate (Clayton et al. 2003;Suddendorf & Busby 2003;Roberts et al. 2008).”

• cites Clayton et al. 2003Not checked yet

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• cites Suddendorf & Busby 2003Not checked yet

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• cites Roberts et al. 2008Not checked yet

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May combine two claims.

Male Mongolian gerbils situated during gestation between two female siblings show up to a 50 per cent increase in alloparental care and lower rates of aggressive behaviour when compared with males situated between two male siblings during gestation.

“male Mongolian gerbils (Meriones unguiculatus) situated during gestation between two female siblings show up to a 50 per cent increase in alloparental care (to offspring that are not their own) and lower rates of aggressive behaviour when compared with males situated between two male siblings during gestation (Clark & Galef 1998, 2000).”

• cites Clark & Galef 1998Not checked yet

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• cites Clark & Galef 2000Not checked yet

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May combine two claims.

Intranasal OT administration increases money transfer by investors in a trust game but has no effect on risk-taking in a non-social context.

“intranasal OT administration increased money transfer by investors in a trust game, but had no effect in risk-taking in a non-social context (Kosfeld et al. 2005).”

• cites Kosfeld et al. 2005Not checked yet

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May combine two claims.

OT increases trusting behaviour and decreases amygdala activation during a trust game.

“OT increased trusting behaviour and decreased amygdala activation during a trust game (Baumgartner et al. 2008).”

• cites Baumgartner et al. 2008Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The formation and maintenance of pairs is a good example of cooperation between two unrelated individuals, as both may benefit from tolerating and supporting each other.

“The formation and maintenance of pairs is a good example of cooperation between two unrelated individuals, as both may benefit from tolerating and supporting each other.”

May combine two claims.

OT- and AVP-releasing neurons project into the midbrain and exert an influence on the mesolimbic dopaminergic reward pathway.

“OT-and AVPreleasing neurons project into the midbrain and exert an influence on the mesolimbic dopaminergic reward pathway (reviewed in Skuse & Gallagher 2009).”

• cites Skuse & Gallagher 2009Not checked yet

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May combine two claims.

Hormones may work through organizational effects during ontogeny, which may cause differentiation between individuals with respect to growth, strength and personality, and which in turn may lead to consistent differences between individuals with respect to behaviour, including levels of cooperation.

“First, hormones may work through organizational effects during ontogeny, which may cause differentiation between individuals with respect to growth, strength and personality, and which in turn may lead to consistent differences between individuals with respect to behaviour; including levels of cooperation (see Bergmuller et al. 2010).”

• cites Bergmuller et al. 2010Not checked yet

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

The amygdala is a danger detection centre activated when a potential threat is detected.

“The amygdala has been viewed as a danger detection centre in the brain, which is activated when a potential threat is detected in the environment (LeDoux 2007).”

• cites LeDoux 2007Not checked yet

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May combine two claims.

In prairie voles, a single injection of OT on the day of birth affects aggressive behaviour and male alloparenting rates.

“In prairie voles, a single injection of OT on the day of birth affects aggressive behaviour (Carter 2003) and male alloparenting rates (Bales et al. 2004).”

• cites Carter 2003Not checked yet

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• cites Bales et al. 2004Not checked yet

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May combine two claims.

Both sex steroids (in particular oestrogens) and glucocorticoids modulate learning and memory processes.

“both sex steroids (in particular oestrogens) and glucocorticoids modulate learning and memory processes.”

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

Hormones can influence learning processes.

“Hormones can influence learning processes.”

May combine two claims.

These effects are mediated by stress hormones, the secretion of which is increased after the separation of the mother from her offspring and decreased again when she is allowed to lick and groom her offspring intensively after the separation.

“These effects are mediated by stress hormones, the secretion of which is increased after the separation of the mother from her offspring and decreased again when she is allowed to lick and groom her offspring intensively after the separation.”

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

Hormones may be involved in other learning and memory tasks relevant for the expression of cooperative behaviour.

“Hormones may also be involved in other learning and memory tasks relevant for the expression of cooperative behaviour.”

May combine two claims.

Patients with lesions of the amygdala fail to recognize fearful faces and display behavioural disinhibition.

“patients with lesions of the amygdala fail to recognize fearful faces and display behavioural disinhibition (Adolphs et al. 2005).”

• cites Adolphs et al. 2005Not checked yet

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Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Unlike neuronal signals, hormones target areas of the brain rather than specific post-synaptic cells, or may reach the entire body, thus influencing systemic adjustments.

“Unlike neuronal signals, hormones target areas of the brain rather than specific post-synaptic cells, or may reach the entire body, thus influencing systemic adjustments.”

May combine two claims.

Administration of AVP soon after birth increases aggressive behaviour in adult male prairie voles and changes risk-taking and social behaviour in rats.

“administration of AVP soon after birth increases aggressive behaviour in adult male prairie voles (Stribley & Carter 1999) and changes risk-taking and social behaviour in rats (Boer et al. 1994).”

• cites Stribley & Carter 1999Not checked yet

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• cites Boer et al. 1994Not checked yet

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Classified as probably not a substantial claim.

In the 'finite state machine theory', Jacobs & Wingfield (2000) explain why different hormones may be linked to the same behaviour during different life-history stages.

“In the 'finite state machine theory', Jacobs & Wingfield (2000) explain why different hormones may be linked to the same behaviour during different life-history stages.”

• cites Jacobs & Wingfield 2000Not checked yet

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May combine two claims.

Year-round cooperative behaviours may be hard-wired by neuronal pathways instead or influenced by hormones only during ontogeny (i.e. organizational effects).

“Year-round cooperative behaviours may be hard-wired by neuronal pathways instead or influenced by hormones only during ontogeny (i.e.organizational effects).”

May combine two claims.

In cooperatively breeding meerkats, glucocorticoids have a positive effect on pup feeding by helpers; helpers with higher glucocorticoid levels provided more food to pups than helpers with low glucocorticoid levels.

“Glucocorticoids also have a positive effect on pup feeding by helpers in cooperatively breeding meerkats (Carlson et al. 2006a).”

• Also stated in: § (a) Organizational effects of hormones and levels of cooperation · plain

  “Helpers with higher glucocorticoid levels provided more food to pups than helpers with low glucocorticoid levels.”

• cites Carlson et al. 2006aNot checked yet

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May combine two claims.

Changes in baseline corticosteroid levels affect social behaviour in various ways, including enhancing foraging, food intake, attention, alertness, and affectionate interactions with infants.

“These changes in baseline levels are known to affect social behaviour in various ways, i.e. by enhancing foraging, food intake (Koch et al. 2002), attention levels and alertness (Chapotot et al. 1998), and also affectionate interactions with infants (Fleming et al. 1997).”

• cites Koch et al. 2002Not checked yet

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• cites Chapotot et al. 1998Not checked yet

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• cites Fleming et al. 1997Not checked yet

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

Major hormones acting on social behaviour in vertebrates include sex steroids, stress steroids, and neurohormones.

“Major hormones acting on social behaviour in vertebrates (adapted from Adkins-Regan 2005).”

• cites Adkins-Regan 2005Not checked yet

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May combine two claims.

Males can be expected to be particularly self-centred during this life-history stage and hence less cooperative.

“males can be expected to be particularly self-centred during this life-history stage and hence less cooperative.”

• AssumptionRests on an assumption: In males, an increase in testosterone prepares the individual for breeding: the size of the gonads increases and sperm production starts, and secondary sexual traits may develop.
• AssumptionRests on an assumption: At the behavioural level, the increase in testosterone levels prepares males to display territorial behaviour, courtship and mating.

May combine two claims.

Both AVP and OT are involved in pair-bond formation in both sexes, with males being more sensitive to AVP, and females to OT.

“Although it was initially thought that AVP and OT would have sex-specific roles in pair-bonding, recent evidence demonstrates that both neuropeptides are involved in pair-bond formation in both sexes, with males being more sensitive to AVP, and females to OT (Young et al. 2008a,b).”

• cites Young et al. 2008a,bNot checked yet

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May combine two claims.

These results reveal a mechanism that allows gregarious species to accentuate the positive valence of social stimuli during social interactions, therefore promoting prosocial behaviour.

“These results reveal a mechanism that allows gregarious species to accentuate the positive valence of social stimuli during social interactions, therefore promoting prosocial behaviour.”

May combine two claims.

Brain administration of a V1a receptor or an OT receptor antagonist prevented mating, but induced partner preference formation, whereas the administration of AVP induced partner preference even without mating.

“Brain administration of a V1a receptor or an OT receptor antagonist prevented mating, but induced partner preference formation, whereas the administration of AVP induced partner preference even without mating (e.g.Winslow et al. 1993;Williams et al. 1994;Lim et al. 2004).”

• cites Winslow et al. 1993Not checked yet

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• cites Williams et al. 1994Not checked yet

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• cites Lim et al. 2004Not checked yet

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

Changes in the weight of each node and in the strength of the connection between each pair of nodes in the brain social behaviour network correlate with behavioural changes within and between species.

“Changes in the weight of each node and in the strength of the connection between each pair of them correlate with behavioural changes within and between species.”

May combine two claims.

Comparative studies of central AVP and OT systems in the vole brain have revealed a conserved pattern of distribution for AVP and OT, but an otherwise divergent pattern between monogamous and promiscuous vole species in terms of distribution of their receptors.

“Comparative studies of central AVP and OT systems in the vole brain have revealed a conserved pattern of distribution for AVP and OT, but an otherwise divergent pattern between monogamous and promiscuous vole species in terms of distribution of their receptors (see Young et al. (2008a,b) for a recent review).”

• cites Young et al. 2008a,bNot checked yet

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May combine two claims.

These differences are associated with the type of social organization and are not necessarily species-specific, since both monogamous prairie and pine voles share a similar pattern of AVP V1a receptor and OT receptor labelling in the brain, whereas promiscuous montane and meadow voles show a different pattern.

“These differences are associated with the type of social organization and are not necessarily species-specific, since both monogamous prairie and pine voles share a similar pattern of AVP V1a receptor and OT receptor labelling in the brain, whereas promiscuous montane and meadow voles show a different pattern (Young et al. 2008a,b).”

• cites Young et al. 2008a,bNot checked yet

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May combine two claims.

In male meerkat helpers, prolactin has an effect on helping behaviour; elevated prolactin levels immediately preceded decisions to babysit.

“In male meerkat helpers, Carlson et al. (2006b) also found an effect of prolactin on helping behaviour.”

• Also stated in: § (a) Organizational effects of hormones and levels of cooperation · plain

  “Elevated prolactin levels immediately preceded decisions to babysit.”

• cites Carlson et al. 2006bNot checked yet

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