2016届高考英语二轮阅读理解九十天强化训练：72_高考复习指南

2016届高考英语二轮阅读理解九十天强化训练：72

　　One showed that adults are much more cooperative if they work in a system based on rewards. Researchers at Harvard University in the United States did the study. They had about 200 college students play a game known as the Prisoner’s Dilemma. The game is based on the tension between the interests of an individual and a group.

　　The students played in groups of four. Each player could win points for the group, so they would all gain equally. But each player could also reward or punish each of the other three players, at a cost to the punisher.

　　Harvard researcher David Rand says the most successful behavior proved to be cooperation. The groups that rewarded it the most earned about twice as much in the game as the groups that rewarded it the least.

　　And the more a group punished itself, the lower its earnings. The group with the most punishment earned 25% less than the group with the least punishment.

　　The other study involved children. Researchers used intelligence tests given to two groups. More than 800 children were ages two to four the first time they were tested.

　　More than 700 children were ages five to nine.

　　The two groups were retested four years later, and the study compared the results with the first test. Both groups contained children whose parents used physical punishment and children whose parents did not.

　　The study says the IQs - or intelligence quotients - of the younger children who were not spanked（掴）were five points higher than those who were. In the older group, the difference was almost three points.