Baby schema modulates the brain reward system in nulliparous women.

Brain Behavior Laboratory, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 06/2009; 106(22):9115-9. DOI: 10.1073/pnas.0811620106
Source: PubMed

ABSTRACT Ethologist Konrad Lorenz defined the baby schema ("Kindchenschema") as a set of infantile physical features, such as round face and big eyes, that is perceived as cute and motivates caretaking behavior in the human, with the evolutionary function of enhancing offspring survival. The neural basis of this fundamental altruistic instinct is not well understood. Prior studies reported a pattern of brain response to pictures of children, but did not dissociate the brain response to baby schema from the response to children. Using functional magnetic resonance imaging and controlled manipulation of the baby schema in infant faces, we found that baby schema activates the nucleus accumbens, a key structure of the mesocorticolimbic system mediating reward processing and appetitive motivation, in nulliparous women. Our findings suggest that engagement of the mesocorticolimbic system is the neurophysiologic mechanism by which baby schema promotes human caregiving, regardless of kinship.

Download full-text


Available from: Ruben Gur, Jul 03, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: “Baby schema” refers to infant characteristics, such as facial cues, that positively influence cuteness perceptions and trigger caregiving and protective behaviors in adults. Current models of hormonal regulation of parenting behaviors address how hormones may modulate protective behaviors and nurturance, but not how hormones may modulate responses to infant cuteness. To explore this issue, we investigated possible relationships between the reward value of infant facial cuteness and within-woman changes in testosterone, estradiol, and progesterone levels. Multilevel modeling of these data showed that infant cuteness was more rewarding when women’s salivary testosterone levels were high. Moreover, this within-woman effect of testosterone was independent of the possible effects of estradiol and progesterone and was not simply a consequence of changes in women’s cuteness perceptions. These results suggest that testosterone may modulate differential responses to infant facial cuteness, potentially revealing a new route through which testosterone shapes selective allocation of parental resources.
    Hormones and Behavior 12/2014; 67. DOI:10.1016/j.yhbeh.2014.11.010 · 4.51 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Facial attractiveness provides a very powerful motivation for sexual and parental behavior. We therefore review the importance of faces to the study of neurobiological control of human reproductive motivations. For heterosexual individuals there is a common brain circuit involving the nucleus accumbens, the medial prefrontal, dorsal anterior cingulate and the orbitofrontal cortices that is activated more by attractive than unattractive faces, particularly for faces of the opposite sex. Behavioral studies indicate parallel effects of attractiveness on incentive salience or willingness to work to see faces. Both work/effort and brain activation to the sight of opposite sex attractiveness is more pronounced in men than women, perhaps reflecting the greater importance assigned to physical attractiveness by men when evaluating a potential mate. Studies comparing heterosexual and homosexual observers indicate the orbitofrontal cortex and mediodorsal thalamus are more activated by faces of the desired sex than faces of the less preferred sex, independent of observer gender or sexual orientation. Infant faces activate brain regions that partially overlap with those responsive to adult faces. Infant faces provide a powerful stimulus, which also elicits sex differences in behavior and brain responses that appear dependent on sex hormones. There are many facial dimensions affecting perceptions of attractiveness that remain unexplored in neuroimaging, and we conclude by suggesting that future studies combining parametric manipulation of face images, brain imaging, hormone assays and genetic polymorphisms in receptor sensitivity are needed to understand the neural and hormonal mechanisms underlying reproductive drives.
    Neuroscience & Biobehavioral Reviews 10/2014; DOI:10.1016/j.neubiorev.2014.08.015 · 10.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Attachments between non-human animals of different species are surprisingly common in situations involving human agency (e.g., homes, zoos, and wildlife parks). However, cross-species animal friendships analogous to pet-keeping by humans are at least rare and possibly non-existent in nature. Why has pet-keeping evolved only in Homo sapiens? I review theories that explain pet-keeping either as an adaptation or an evolutionary by-product. I suggest that these explanations cannot account for the wide variation in the distribution and forms of pet-keeping across human societies and over historical time. Using fluctuations in the popularity of dog breeds in the United States, I show how shifts in choices of pets follow the rapid changes in preferences that characterize fashion cycles. I argue that while humans possess some innate traits that facilitate attachment to members of other species (e.g., parental urges, attraction to creatures with infantile features), pet-keeping is largely a product of social learning and imitation-based cultural evolution. Are humans the only animal to keep pets, and if so, why? The public is fascinated by reports of attachments between non-human animals of different species (henceforth "animals"). This is not a new phenomenon. For example, a lion and lamb which had formed a special friendship were put on public display in London in 1654 (Thomas, 1984). Today, affectionate relationships between animal "odd couples" are among the most widely viewed of animal YouTube clips (Nelson & Fijn, 2013). Natural history television specials depicting inter-species relationships have recently aired in the United States and in the United Kingdom, and books with titles such as Unlikely Friendships: 50 Remarkable Stories from the Animal Kingdom (Holland, 2011) have become bestsellers. Among the more famous cases of inter-specific friendships are the relationships between Koko, a sign-language trained gorilla, and a kitten (Patterson & Cohn, 1985); Mzee, an orphaned hippopotamus in Kenya, and a 160-year-old giant tortoise (Hatkoff et al., 2006); and Tarra, an Asian elephant, and a dog named Bella (Buckley, 2009). A few systematic studies have also demonstrated that animals have the capacity to become attached to members of other species. In an early experiment, Kuo (1930) found that six of eighteen kittens raised with rats became strongly attached to their rodent cage-mates, and wrote, "Indeed, if cats have an instinct of love, certain of my kittens have "shown" it in their response to rats" (p. 26). Mason and Kenny (1974) paired juvenile rhesus monkeys with adult dogs. Within a few hours after being introduced, the dogs and monkeys showed clear signs of attachment. After several months living together, each monkey was given a choice between interacting with the dog it was paired with, a strange dog, or another monkey. In nearly all cases, the monkeys chose to associate with the dog they had become attached to. The problem, however, is that all of these cases of long-term inter-specific attachments have occurred in situations involving significant human intervention such as households, zoos, and wildlife parks in which the animals were provisioned. In some well-known cases, the cross-species interactions
    05/2014; 2014(1):296-308. DOI:10.12966/abc.08.06.2014