To test the effectiveness of using a dab of honey to prevent infection in a cut, parents of children in a childcare facility were instructed to wash the wounds of their children with soap and water and then place a dab of honey on the cut. each cut was then monitored for infection. at the end of the study, the percentage of the twenty eight children who had cuts that became infected was computed. does this study have randomization?

This is this not a valid experiment because there is no randomization. T here is no blinding as parents may use more care and those monitoring for infection may be less stringent in their diagnosis.  There is no control group that gets a placebo for comparison.  Parents may be more careful of the cuts of their children since they know they are in an experiment. And t he results may not apply to all children since only those children in a day care facility participated.

as university of miami psychologists debra lieberman and adam smith pointed out in a recent article in the journal current directions in psychological science, humans have social and psychological mechanisms to deter incest. with very few exceptions, marriages between brothers and sisters and between parents and their children are verboten in every human culture. the primary psychological anti-incest mechanism is the yuck response. even the idea of sex with their mom or dad, bro or sis is upsetting to most people. the psychologist jonathan haidt has found that nearly everyone is repelled by the prospect of brother-sister sex, even in hypothetical situations in which there is no chance of pregnancy).

the biological cost of incest

this raises an interesting question: just what’s so bad about incest? sure, having sex with your dad or your sister seems gross — but why? some anthropologists have argued that incest taboos are learned social conventions. this explanation, however, doesn’t make sense to me as it does not explain the widespread existence of anti-incest mechanisms in creatures ranging from cockroaches to chimpanzees. second, the incest taboo is about as close to a universal law as human moral rules get.

why should mechanisms to avoid incest be so widespread both in nature and across human societies? the answer is simple. the problem with having sex close with relatives is that there is an astonishingly high chance that your offspring will be born with a serious birth defect.