Robert L. Trivers
Distinguished Professor of Anthropology and Biological Sciences
Department of Anthropology
New Brunswick, New Jersey 08901-1414
(732) 932-1564 (fax)
|A new book by Robert Trivers, Brian G. Palestis, and Darine Zaatari
The Anatomy of a Fraud: Symmetry and Dance
(2009, TPZ Publishers)
|Book by Austin Burt and Robert Trivers,
GENES IN CONFLICT: the Biology of Selfish Genetic Elements
(2006, Harvard University Press)
(Click here for a detailed outline of the chapters.)
Social evolution, natural selection and social theory, evolution of selfish genetic elements
Fluctuating asymmetry in Jamaican children (see below ), deceit, and self-deception
Long-term study of fluctuating asymmetry (degree of bodily and behavioral symmetry) in 288 Jamaican schoolchildren and its social and biological correlates, e.g. how does symmetry correlate with attractiveness, dancing ability, aggressiveness, # of friends, health status, growth rate, academic achievment, athletic ability etc. - More detailed information below .
PUBLICATIONS SINCE 2000 and selected earlier ones
Manning, JT and Trivers, R. submitted. Maternal waist-to-hip ratio and children’s digit ratio from X-rays and photocopies: evidence for a soft-tissue effect of prenatal androgen on 2D:4D. American Journal of Human Biology
Zaatari, D. and Trivers, R. 2007. Fluctuating asymmetry and behavior in the ultimatum game in Jamaica. Evolution and Human Behavior 28: 223-227. [pdf]
Trivers, R., Manning, J.T., and Jacobson, A. 2006. A longitudinal study of digit ratio (2D:4D) and other finger ratios in Jamaican children. Hormones and Behavior 49: 150-156. [pdf]
Burt, A., and Trivers, R. 2006. Genes in Conflict: The Biology of Selfish Genetic Elements. Cambridge, Harvard University Press.
Brown, W.M., Cronk, L., Grochow, K., Jacobson, A., Liu. C.K., Popovic, Z. and Trivers. R. 2005. Dance reveals symmetry especially in young men. Nature 438: 1148-1150. [pdf]
Trivers, R. 2005. Reciprocal altruism: 30 years later. In C.P. van Schaik and P.M. Kappeler (eds.) Cooperation in Primates and Humans: Mechanisms and Evolution. Berlin: Springer-Verlag, pp 67-83. [pdf]
Levin, DA, Palestis, B.G, Jones, R.N and Trivers, R. 2005. Phyletic hot-spots for B chromosomes in Angiosperms. Evolution 59: 962-969. [pdf]
Trivers, R. 2004. Mutual benefits at all levels of life. Science 304: 964-965. [pdf]
Manning, J.T., Stewart, A, Bundren, P.E., and Trivers, R.L. 2004. Sex and ethnic differences in 2nd to 4th digit ratio of children. Early Human Development 80:161-168. [pdf]
Penton-Voak, I.S., Jacobson, A., and Trivers, R. 2004. Population differences in attractiveness judgments of faces: comparing a British and Jamaican sample. Evolution and Human Behavior 25: 355-370 [pdf]
Palestis, B.G., Trivers, R. Jones, R.N. and Burt, A. 2004. The distribution of B chromosomes across species. Cytogenetics and Genome Research 106: 151-158.
Trivers, R, Burt, A, and Palestis, B.G. 2004. B chromosomes and genome size in flowering plants. Genome 47:1-8 [pdf]
Palestis, B.G., Burt, A., Jones, R.N. and Trivers, R. 2004. B chromosomes are more frequent in mammals with acrocentric karyotypes: support for the theory of centromeric drive. Proc. Royal. Society. B Suppl.271: S22-S24. [pdf]
Trivers. R. 2002. Natural Selection and Social Theory: Selected Papers of Robert Trivers. New York: Oxford University Press.
Cashdan, E, and Trivers, R. 2002. Self-deception. In M. Pagel (ed.) Encyclopedia of Evolution. New York: Oxford University Press.
Manning, J., Martin, S., Trivers, R., and Soler, M.. 2002. 2nd to 4th digit ratio and offspring sex ratio. J. theor Biology 217: 93-95.
Manning, J.T., Barley, L., Walton, J., Lewis-Jones, D.I., Trivers, R.L., Singh, D., Thornhill, R., Rohde, P., Bereckie, T., Henzi, P., Solder, M., and Szwed, A. 2000. The 2nd:4th digit ratio, sexual dimorphism, population differences and reproductive success: evidence for sexually antagonistic genes. Evolution and Human Behavior 21: 163-183.
Trivers, R. 2000. The elements of a scientific theory of self-deception. Annals NY Acad Sciences 907: 114-131. [pdf]
Manning, J.T., Trivers, R., Thornhill, R. and Singh, D. 2000. The 2nd:4th digit ratio and hand preference in Jamaican children. Laterality 5: 121-132.
Trivers, R, Manning, JT, Thornhill, R, Singh, D. and McGuire, M. 1999. The Jamaican symmetry project: a long-term study of fluctuating asymmetry in rural Jamaican children. Human Biology 71: 419-432.
Seger, J. and Trivers, R. 1986. Asymmetry in the evolution of female mating preferences. Nature 319:771-773.
Trivers, R. 1985. Social Evolution. Benjamin/Cummings, Menlo Park, CA.
Trivers, R. L. and Newton, H. P. 1982. The crash of Flight 90: Doomed by self-deception? Science Digest, November, pp. 66, 67 and 111.
Trivers, R. L. 1976. Sexual selection and resource-accruing abilities in Anolis garmani. Evolution 30:253-269.
Trivers, R. L. and Hare, H. 1976. Haplodiploidy and the evolution of the social insects. Science 191:249-269.
Trivers, R. L. 1974. Parent-offspring conflict. American Zoologist 14:247-262.
Trivers, R. L. and Willard, D. 1973. Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90-92.
Trivers, R. L. 1972. Parental investment and sexual selection. In B. Campbell, ed. Sexual Selection and the Descent of Man, 1871-1971, Aldine-Atherton, Chicago, pp. 136-179.
Trivers, R. L. 1971. The evolution of reciprocal altruism. Quarterly Review of Biology 46:35-57. [pdf]
The Rutgers Jamaican Symmetry Project is a long-term research project studying the degree of symmetry in children and its various correlations in their lives. The project is funded out of Rutgers University in New Brunswick, New Jersey. under the direction of Dr Robert Trivers, who is a Professor of Anthropology and Biological Sciences at Rutgers and a long-time resident of Southfield in St Elizabeth. The research is centered at the Top Hill Primary School and operates with the help of the teachers there and its Principal, Mr Vernon Cameron. Some children are also drawn from the nearby schools of Mayfield Primary and Epping Forest All-Age.
In January, 1996, 288 children were measured for degree of symmetry--the degree to which the two sides of the body are similar or identical. Ten measurements were taken on each child with calipers (wrists, ankles, elbows, fingers, ears and so on). In addition, each child's hands were X-rayed, a cast was made of the upper teeth, a photo of the face was taken, a full set of palm and fingerprints was made, and the degree to which the right hand performed better or worse than the left hand was measured. Most of this information has been entered onto computers and is now being analyzed. This information forms the foundation for all other work and is the most detailed set of bodily measurements on symmetry available for any group of human beings anywhere in the world. Since these measurements are on children (then between the ages of 6 and 11) they are especially valuable because the children can be followed throughout their lives. We are especially interested in the health of the children, their long-term growth and development and the social behavior they display.
To date we have gathered information on the families of our children (from the parents), their academic achievement (from school records), the frequency of aggressive behavior in school (from the teachers), their dancing ability, their attractiveness to others, their number of freiends and the degree to which they are rated as aggressive by their classmates. We hope soon to give the children a series of psychological tests and later to study their behavior in more detail. Remeasurements of the children for symmetry and for growth are planned for a later date as well. We also plan complete medical and dental evaluations of our children.
The first article based on the research has appeared in the journal Evolution and Human Behavior. It shows that Jamaican schoolgirls are more likely to cradle a doll on the life side of their bodies if their ears are more symmetrical, while symmetry elsewhere (for example, of their fingers or elbows) is unrelated to the tendency to cradle on the left-hand side. Jamaican boys show no over-all tendency to cradle on the left-hand side and no association with symmetry of ears or any other body part. In this, Jamiacan children resemble British adults: women tend to cradle their babies on the left side if their ears are more symmetrical (but not other body parts) while men show no cradlng bias. We interpret these results as making sense because information going into the left ear (and left visual field) go immediately to the right half of the brain, which is specialized for interpreting emotional information (such as is conveyed in a baby's voice and actions). This specialization is particularly well-developed in women and we believe that asymmetry of the ears partly reflects a breakdown of the usual pattern.
Recent discoveries include the fact that the lower body (ankles, feet and knees) are
by far the most symmetrical part of the body (sides differ by about 0.7%.. Average upper body asymmetry is about 2.3% and the elbow, at 3.5%, is the most assymetrical part. The Jamaican children are more symmetrical than a comparable sample of English children, boys are ever so slightly more symmetrical than girls, primarily due to their symmetrical elbows. Size increases absolute asymmetry, while age is associated with greater symmetry.
Recently we have shown that lower body asymmetry more strongly predicts (negatively) aggressiveness, just as in samples of other boys and young men in the U.S. and England.
Each child is identified by a number and all the scientific information is stored by reference to a child's number. Each child is paid to a modest sum to participate in the project. In addition to teachers and principals, Jamaican students are also employed to help with the project. We gratefully acknowledge the permission of the Ministry of Education and Culture and the cooperation of the three schools in St Elizabeth, especially the Top Hill Primary School.
Our aim is to follow these individuals if possible into adulthood. We are actively measuring a series of variables: academic achievement (higher with lower dermatoglyphic asymmetry), dancing ability (in boys more symmetrical are better), attractiveness (positive in symmetry in the girls, running ability (data not yet analyzed) and so forth.
Senior scientists overseeing the project in addition to Dr Trivers are Dr John Manning (Uiversity of Liverpool), Dr Randy Thornhill (University of New Mexico), Dr Devendra Singh (University of Texas) and Dr Richard Jantz (University of Tennessee).