All countries benefit from each of the following factors except which one?
a. access to information
b. good relations among government
c. no glaring inequalities between trading partners
d. always producing the product that the country has absolute advantage in producing

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.

new communications technology has affected the way social movements are organized because nowadays, social movements rely on social networks and the media to get different people with a similar way of thinking in contact, and thus, get them to mobilize for a greater cause.

individuals only participate in collective action when they feel identified with it. is in this aspect that social media becomes relevant, because it guarantees communication among all individuals and organizes the social actions that are going to be carried out, i.e., the social movements.

in addition, being covered by the media is important to validate the message and make it relevant in the social agenda, as well as to reach more people who can share interests, appealing to public sympathy for their cause.

in conclusion, it is by social networks and social media that social movement is given birth; by connecting different individuals with similar ideas and organizing them to mobilize for a greater cause.