Research Report The Cutest Little Baby Face A Hormonal Link to Sensitivity to Cuteness in Infant Faces R. Sprengelmeyer, 1 D.I. Perrett, 1 E.C. Fagan, 1 R.E. Cornwell, 1 J.S. Lobmaier, 1 A. Sprengelmeyer, 2 H.B.M. Aasheim, 1 I.M. Black, 1 L.M. Cameron, 1 S. Crow, 1 N. Milne, 1 E.C. Rhodes, 1 and A.W. Young 3 1 University of St. Andrews, 2 Universita¨t Bielefeld, and 3 University of York ABSTRACT—We used computer image manipulation to de- velop a test of perception of subtle gradations in cuteness between infant faces. We found that young women (19–26 years old) were more sensitive to differences in infant cuteness than were men (19–26 and 53–60 years old). Women aged 45 to 51 years performed at the level of the young women, whereas cuteness sensitivity in women aged 53 to 60 years was not different from that of men (19–26 and 53–60 years old). Because average age at menopause is 51 years in Britain, these findings suggest the possible involvement of reproductive hormones in cuteness sensitivity. Therefore, we compared cuteness discrimina- tion in pre- and postmenopausal women matched for age and in women taking and not taking oral contraceptives (progestogen and estrogen). Premenopausal women and young women taking oral contraceptives (which raise hormone levels artificially) were more sensitive to varia- tions of cuteness than their respective comparison groups. We suggest that cuteness sensitivity is modulated by female reproductive hormones. More than half a century ago, Konrad Lorenz proposed the Kindchenschema as an innate releasing mechanism for care- taking behavior and affective orientation toward infants, trig- gered by features such as protruding cheeks, a large forehead, and large eyes below the horizontal midline of the skull (Lorenz, 1943). Baby faces having these features are commonly de- scribed as cute, and although cuteness has been shown to modulate mother-infant interaction (Langlois, Ritter, Casey, & Sawin, 1995), there are only a few psychophysical studies in- vestigating responses of men and women to variations of phys- ical properties of baby faces (Alley, 1981; Brooks & Hochberg, 1960; Gardner & Wallach, 1965; Hu ¨ ckstedt, 1965; Sternglanz, Gray, & Murakami, 1977). Overall, findings from these studies are not conclusive but suggest a possible difference between men and women in perceiving cuteness. However, a question not addressed in previous studies concerns what might underlie any sex differences in adults’ ability to perceive infant cuteness. An obvious cause might be differential interest in babies, but there are other explanations. Given that Lorenz had conceived the Kindchenschema as a biological mechanism, we decided to investigate the possibility of a link to female reproductive hormones. STUDY 1 Study 1 aimed to explore the idea of a possible link between cuteness perception and female reproductive hormones by looking at groups of younger women, younger and older men, and women aged slightly below and above the average age at menopause in Britain. Method Participants Twenty-four younger women (mean age 5 22.0 years, SD 5 1.8 years, range 5 19–26 years), 24 younger men (mean age 5 21.5 years, SD 5 1.5 years, range 5 19–26 years), and 24 older women (mean age 5 53.2 years, SD 5 4.1 years, range 5 45–60 years) were investigated. Bearing in mind that reproductive hormones might possibly modulate sensitivity to infant facial cuteness, we used the older women’s median age of 52 years (which is near the average age at menopause in Britain) to subdivide the latter group into a group of women aged 51 years and younger (mean age 5 49.8 years, SD 5 2.1 years, range 5 45–51 years), and a group of women aged 53 years and older (mean age 5 56.6 years, SD 5 2.5 years, range 5 53–60 years). No participant was taking hormone-replacement therapy or had undergone hysterectomy. At a later stage of the study, a group of 11 older men (mean age 5 56.5 years, SD 5 2.3 years, range 5 53–60 years) was added to provide a point of comparison to the women aged 53 through 60 and to the younger men. Address correspondence to R. Sprengelmeyer, School of Psychology, University of St. Andrews, St. Andrews KY16 9JU, Scotland, e-mail: rhs3@st-and.ac.uk. PSYCHOLOGICAL SCIENCE Volume 20—Number 2 149 Copyright r 2009 Association for Psychological Science