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The relationship between psychological stress and reduced fecundity has been a matter of speculation and investigation for decades. Most previous studies have been compromised, however, by a number of problems including ambiguous direction of causation, poorly operationalized variables, and the confounding of psychological with energetic stress. We presenta two-part study of the relationship between moderate anxiety, both acute and chronic, and daily measures of ovarian steroid and corticosteroid levels in saliva. Anxiety, as a particular form of psychosocial stress, was measured by the Spielberger Stait-Trait Anxiety Inventory as well as by a self-reported daily stress score. In the first part, 23 college juniors taking the Medical College Admissions Test (MCAT) were studied the month before and the month after the test, and again several months later, and compared at the same time points with 27 controls. In the second part, chronic anxiety levels were assessed in 95 women between 27 and 41 years of age and analyzed in relation to daily levels of salivary ovarian and corticosteroids over one menstrual cycle. The sample sizes are sufficient to allow for confidence in negative results. No statistically significant differences in ovarian of corticosteroid levels were observed whether between the MCAT and control subjects in part one, between the MCAT subjects before and after the MCAT test in part one, or between high and low anxiety subjects in part two. The results indicate that moderate levels of anxiety, whether acute or chronic, are not associated with suppressed ovarian function in healthy women. KEY WORDS ovarian function; stress; anxiety; estradiol; progesterone

The study of comparative energetics offers a valuable way to identify broad ecological principles and assess the functional significance of energetic adaptations during the course of evolution. Yet, the quantification of energetic status for nonhuman primates under natural conditions remains one of the most challenging aspects of comparative energetics research. Here, we report on the development of a noninvasive field method for measuring energetic status in great apes, humans, and possibly other nonhuman primates. Specifically, we have explored measurement of a urinary metabolite of insulin (C-peptide) as a physiological marker of energetic condition in chimpanzees and orangutans. We performed three validation studies and successfully measured C-peptide in urine samples from captive chimpanzees, wild chimpanzees, and wild orangutans. Urinary C-peptide measures gave indications of being a reliable signal of energetic status in both species. For chimpanzees and orangutans in the wild, baseline urinary C-peptide levels were higher during periods of fruit abundance than periods of low fruit availability. Urinary C-peptide levels were also higher for well-fed captive chimpanzees compared with wild chimpanzees. Although sample size was small, top-ranking male chimpanzees showed higher C-peptide levels in the wild than low-ranking males only during the period of fruit abundance. These preliminary results indicate that further development of the urinary C-peptide method could expand opportunities to quantify energetic condition for great apes in the wild and generate new data for comparative research. We highlight specific applications for studying great ape reproduction as well as the nutritional ecology of human foragers. KEY WORDS endocrinology; metabolism; great apes; human foragers; field method

A study to show that ponderal index at birth predicts high estradiol levels in adult women is presented. Conditions during fetal life influence adult production of reproductive hormones and may contribute to inter-individual variation in reproductive function and there is a physiological link for the observed positive relationship between indicators of energetic conditions during fetal growth and breast cancer in women.

This paper presents results of a study designed to: 1) test for a sex difference in the relative lengths of the finger bones, including the second-to-fourth digit ratio (2D:4D), using left-hand radiographs taken in young children, 2) test whether sex differences can be explained by sex differences in fetal growth, and 3) test the serial stability of sex differences in relative digit lengths, including 2D:4D. Results are presented from 1,060 subjects of the California Child Health and Development Studies. One serial replication at about 9 years old is available from 271 subjects. Results indicate that relative digit lengths are sex-dimorphic in children (Manning et al. [1998] Hum. Reprod. 13:3000-3004, [2004] Early Hum. Dev. 80:161-168). Sex differences in digit length ratios are more pronounced within sibships, where shared family factors are controlled, and are not strongly associated with gross measures of fetal growth, like birth length or weight. Thus, sex differences in the fetal growth of the body are not implicated in sex differences in digital formulae, leaving open the possibility of more direct hormonal and/or genetic causation. However, 2D:4D declined between ages 6-8 in a longitudinal sample, and was a less consistent sex-dimorphic marker than 3D:4D across ethnic groups, suggesting that 3D:4D may be a better marker of perinatal sex differentiation. Prior conflicting findings about 2D:4D may be partly explained by variations in age and ethnicity of populations studied. KEY WORDS second-to-fourth digit ratio; 2D:4D; digit ratios; sex dimorphism; sex differences