One of the most important issues facing legal and medical policy makers in the coming years will be whether to employ populationbased testing for genetic markers of inherited diseases. Two hundred and twenty-six randomly selected individuals from Easton, Pennsylvania completed a mail questionnaire that was designed to assess the general public's attitudes toward many of the personal and societal issues surrounding genetic testing for disease susceptibility. Respondents were generally optimistic about the potential benefits of genetic testing, and their attitudes about genetic testing were associated with their personal interest in getting a genetic test. Respondents were more likely to be interested in undergoing genetic testing for disease susceptibility if they might have some control over the targeted disease (i.e. there was a cure) and if the test was highly predictive of their chances of developing the disease. Respondents were wary of granting access to genetic testing results to anyone other than doctors and family members, and they did not want the government, religious leaders, or the courts involved in regulating genetic testing. These results have important implications for psychologists, genetic scientists, bioethicists, and legal scholars who are grappling with the many issues related to population-based genetic testing for inherited diseases.

The onset of circadian rhythms in many animals occurs during prenatal development. We conducted four experiments, using the domestic chick as a model, to assess when these rhythms can first be entrained and the type of light zeitgeber necessary. In Experiment 1, the presence of circadian rhythms was assessed using tonic immobility, an antipredator behavior, whereas in Experiments 2 to 4 body temperature was studied. We demonstrate that (a) circadian rhythms can be entrained during the late stage of the chick's 21-day incubation period (prehatch Days 13-18), (b) only 1 day of light cues [12:12 hr light:dark (12L:12D)] on prehatch Day 13 is necessary for entrainment, and (c) short bouts of light, which simulate the light cues embryos typically experience during natural incubation, can act as zeitgebers although they are not as effective as 12L:12D. The onset of entrainment is earlier than predicted and suggests that the brain structures mediating circadian rhythms mature sooner than proposed by previous research.