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Psychologists used to believe that greater prejudice among older adults was due to the fact that older people grew up in less egalitarian times. 【R1】__________ The frontal lobes are the last part of the brain to develop as we progress through childhood and adolescence, and the first part of the brain to atrophy as we age. Atrophy of the frontal lobes does not diminish intelligence, but it degrades brain areas responsible for inhibiting irrelevant or inappropriate thoughts. Research suggests that this is why older adults have greater difficulty finding the word they're looking for and why there is a greater likelihood of them voicing ideas they would have previously suppressed. 【R2】__________ At Williams College in Massachusetts, an African-American student said her white grandfather had recently started referring to her as his "little nigger grandchild". She was shocked and hurt by this, and couldn't understand why her grandfather would say such a thing when she knew he loved her and was still mentally alert. The consequences of his disinhibited words were substantial, although he was creating friction only with family and friends. Researchers have found evidence of a variety of problems of this kind. For example, older adults in experiments are more likely than younger adults to rely on stereotypes and they have more difficulty than younger adults suppressing their stereotypic thoughts. 【R3】__________Furthermore, all of these effects only emerge among older adults who show signs of poor frontal lobe functioning. There are two ways of interpreting the disinhibited expressions of older adults. Perhaps such statements reveal people's true personality, finally emerging now that they can no longer suppress their beliefs. 【R4】__________ Alternatively, it may be the case that our inhibitory abilities don't suppress our personality but rather help shape it. According to one researcher, some of the children in her primary school used to shove snow down the jacket of a boy who had muscular dystrophy, because his physical disability prevented him from protecting himself. These children may have grown into adults who truly believe it is morally reprehensible to torment disabled children, but it is quite likely that they rely on their inhibitory ability to keep their earlier and more primitive attitudes in check. 【R5】__________ [A] But it doesn't stop there—researchers also find that older adults are more likely to be socially insensitive across a variety of domains. [B] In other words, strip away the political correctness enabled by the frontal lobes, and you learn what the student's grandfather had really been thinking all these years. [C] Famous people are at a disadvantage when their frontal lobes start to shrink, as many of their utterances are part of the public record. But disinhibition is also costly for people outside the public eye. [D] Such changes in social attitudes are not inevitable, but they are common. And the people who find themselves becoming less tolerant or more prejudiced can be quite unsettled by the shift in their own attitudes—a change that can affect friendships and their position in society. [E] From this perspective, inhibitory ability isn't stopping people's true opinions from emerging so much as it's suppressing their prior opinions. The research indicates that older adults simply have greater difficulty suppressing prejudices than younger adults do. [F] But psychologist William von Hippel says it should not necessarily be a surprise—he argues that it's not usual for people to become more prejudiced as they get older. [G] In contrast to this view, recent research shows that normal changes to the brain in late adulthood can lead to greater prejudice among older adults.