The nature of love

“In his classic work “The Nature of Love,” Harlow (1958) described how infant macaque monkeys raised in isolation clung to the most companion-like objects available in his laboratory—warm, terrycloth-covered structures.”

“Probably the most important of these is the line of “ethological” work on attachment, separation, and loss, running from Harlow (1958) through Winnicott (1960), Bowlby (1969), to Ainsworth (Ainsworth, Blehar, Waters & Wall, 1978) and Fonagy and colleagues (e.g., Fonagy, Steele, & Steele, 1991;…”

“…mothers’ were then developed, to which neonatal monkeys became attached and could be pacified by these ‘mothers’ when stressed, but only when these mothers were covered in a soft layer of cotton terry cloth, with no real benefit of a wire ‘mother’ at all (Harlow 1958; Harlow and Suomi 1970).”

“Around 60 years ago, Harlow and Zimmerman demonstrated the importance of tactile comfort in primate development (Harlow, 1958, p. 19).”

“Adolescent loneliness may be explained using attachment theory, which is built on the assertion that young children's attachment bonds with parents or primary caregivers are biological and essential to survival and development (Bowlby, 1973, 1982; Harlow, 1958).”

“In the absence of maternal attachment and physical contact, both human and animal infants display behaviors that are antithetical to security—fear and wariness—and evince a reduced tendency to explore their physical space (Ainsworth et al., 1978; Harlow, 1958).”

“The authors argue that because of frequent early life experiences with loving family members [39,40] a close mental association may develop between the concepts of physical warmth and psychological warmth.”

“Thermal Affective Feedback There are inherent links between thermal sensation and emotion, such as the need for physical warmth for psychosocial development of infants [10,17], or the associations of words such as “loving” to “warm” personalities [5,15].”

“Classic experiments by Harlow [82] demonstrated that social interaction is required for normal emotional development in macaques.”

“Attachment theorists stress the importance of physical contact with caregivers (and the concomitant warmth [19]) for the proper social and psychological development of infants [5].”

“Based on these experiments, Harlow concluded that contact comfort is overwhelmingly important for normative social development (Harlow, 1958).”

“Both groups of monkeys spent significantly more time with the cloth "mother," especially in times of distress when they climbed on and clung to "her", despite the fact that only one group could get any actual food from the cloth "mother" (Harlow, 1958; Harlow and Zimmerman, 1959).”

“This need concerns the desire to form and maintain strong and stable interpersonal relationships, to connect with and be accepted by others, and to belong (Baumeister & Leary, 1995; Bowlby, 1979; Harlow, 1958; Ryan, 1995).”

“…that bond do so by getting in close proximity with one another, gently touching or grooming each other, or hugging and kissing (de Waal, 1989; Harlow, 1958; Maestripieri, 1998; Orlaith, Stahl, & Aureli, 2008; Slater, Schaffner, & Aureli, 2007; see also Fiske (2004) on body contact as…”

“The work of Harlow and his colleagues demonstrated that, in conditions of stress, infant macaques showed clear preference for cloth surrogate "mothers" over wire mesh "mothers", even though the latter were sources of food (Harlow, 1958).”

“He linked psychoanalysis to ethological findings on imprinting and following behaviors (Lorenz, 1949) and the psychological research carried out on young Macaques’ attachment to their mother (Harlow, 1958); consequently, Bowlby formulated a theory of attachment that was valid for all mammals.”

“children with secure attachment styles are more likely to explore unfamiliar environments, presumably because their secure attachment fosters the perception that they will be protected in the event of negative consequences, which makes the environment seem less dangerous (Ainsworth, Blehar, Waters, & Wall, 1978; Harlo…”

“behavior in rhesus infants (Harlow, 1958), and surrogate-reared infants exhibit attachment behavior that is comparable to that of mother-reared infants.”

“Harlow in the mid-20th century [35], which emphasized the importance of gentle physical contact in an infant rhesus monkey’s tendency to bond with its mother.”

“Building on Harlow's ( 1958 ) classic research on primates, Bowlby established a theory of development to explain the “goal-corrected partnership” (Ainsworth, 1989 ; Bell & Ainsworth, 1972 ) that evolves between a child and a primary caregiver wherein the child uses the caregiver as a secure base and a haven of safety.”

“An affectional explanation to touch has been proposed to have biological underpinnings that shape our behaviors by suggesting that, “we believe that contact comfort has long served the animal kingdom as a motivating agent for affectional responses” (Harlow, 1958, p. 676).”

“…inferences can be learned via three paths: phylogenetic learning (natural selection of inherited instincts, i.e., evolutionary preparedness; Harlow, 1958), ontogenetic learning (e.g., classical and instrumental conditioning; Pearce, 1997), and, for some species, social learning (Richerson…”

“of isolated monkeys by William Mason (1960) and Harry Harlow (1958) take apart the stimulus properties of the infant monkey’s mother object into various components with devastating effects on the monkey’s adult social and reproductive behavior.”

“Being in contact with other individuals is a basic need of humans (as well as of numerous other species; Harlow, 1958), and social isolation is a major risk factor for morbidity as well as mortality (Cacioppo & Hawkley, 2003; House, Landis, & Umberson, 1988).”

“Young mammals crave close contact with their maternal caregiver (Harlow, 1958; Denenberg, 1968) and humans are no exception (Korner and Thoman, 1972; Brazelton, 1990).”

“Contact comfort is universally perceived as reassuring by both human infants (e.g., Wolff, 1969) and infants of nonhuman primates (e.g., Harlow, 1958).”

“In one study (Harlow, 1958), infant monkeys were taken away from their mothers and placed in a cage with two types of surrogate mothers.”

“Various successive developmental steps of precursor cells, precursor peptides, as well as precursor receptors of oxytocin characterize this evolutionary progression (19).”

“Additionally, these studies establish a mechanistic substrate underlying infant-caregiver interaction, which suggests an initial population of neurons underlying the long-sought nature of this social bond in mammals (Harlow, 1958; Lewis et al., 2007).”

“Observations of distressed children away from their parents as well as the animal experimental work by Harry Harlow on social deprivation (Harlow 1958) led the British psychologist John Bowlby to formulate his theory on attachment as fundamental within the development of the person (Bowlby 1951, 1984).”

“…were infamous for their cruelty) on maternal deprivation in rhesus monkeys were performed by Harlow in the 1950s, ’60s, and ’70s; later, Suomi conducted similar maternal deprivation experiments on infant monkeys (Harlow, 1953, 1958; Harlow and Zimmermann, 1959; Harlow and Suomi, 1971; Suomi, 2011).”

“In his famous experiments, infant rhesus monkeys were taken from their mothers and ‘raised’ by either a terry-cloth or wire surrogate, all else being held constant [ 16 ].”

“The second hypothesis was that high tr3it anxiety subjects would respond differently than low trait anx iety subjects, Yet no significant differences in the mean heart rate were found between these two groups, Similarly, no significant differences in pretest STAI scores were found for either the high trait anxi etyor…”

“Experiments surrounding relationship attachment by Harlow outlined in his well-known thesis The Nature of Love established that distressed monkeys choose realism in substitute kin over functionality [43].”

“General recognition of the importance of a warm, nurturing relationship and the establishment of a secure emotional bond with a caregiver, for adaptive psychological development, dates back to the Harlow monkey experiments (Harlow, 1958).”

“Third, the need for relatedness concerns the desire to form and maintain strong and stable interpersonal relationships, to connect with and be accepted by others, and to belong (Baumeister and Leary 1995; Bowlby 1979; Harlow 1958; Ryan 1995).”

“Moreover, interpersonal touch can predict outcomes ranging from maintaining loving relationships (Gallace & Spence, 2010; Harlow, 1958) to tipping at restaurants (Stephen & Zweigenhaft, 1986).”

“Harry Harlow (1958) was the first to use the term “love” to refer to this strong emotional bond between the mother and her infant.”

“The psychological significance of touch has been studied in social and emotional development (e.g., Harlow, 1958; Spitz, 1945) and as a means of communication (e.g., Henley, 1973; 1977; Jones & Yarbrough, 1985; Major, 1981 ; Stier & Hall, 1984; Thayer, 1986a, 1986b).”

“Harry Harlow's experiments on contact comfort come immediately to mind (Harlow 1958).”

“We know that our first intimate or loving relationship with our primary caregiver informs our expectations and patterns of behaviour (Harlow, 1958).”

“Belgian authors sometimes use the term ‘gestational child’ (Innes, 2013). UK psychologist van den Akker (2000) used the term ‘surrogate baby,’ and writing with social work colleagues later referred to ‘children born through surrogacy’ (Crawshaw et al.”

“In the cognition and behaviour domains, studies with captive primates have made relevant contributions to psychology and neuroscience, as exemplified by Harlow’s experiments on “the nature of love” [13] or Selemon and Goldman Rakic’s [14] early brain topography studies.”

““The recent writings of John Bowlby” are mentioned in the published paper ( Harlow 1958, p. 673 ), to the effect that he recognized the mother’s importance in providing the infant with intimate physical contact, as well as serving as a source of nutrition.”

“Despite this pronouncement, the need for affection became widely accepted only after the famous study of rhesus monkey infants by Harlow (1958), Maslow’s teacher.”

“Perhaps the most paradigmatic example is Harry Harlow and his experiments on maternal separation, dependency needs, and social deprivation (for an overview on Harlow’s research see Harlow 1958; Harlow et al.”

“Although there is comparatively little work in this area, a framework for the ecological study of such social perception has been established (Rogoff, 1990; Zebrowitz, 1990; Zebrowitz & Baron, 1983; but also see Asch, 1960; Harlow, 1958; Lewin, 1951).”