Which of these is LEAST characteristic of children with Down syndrome?

Sandra has experienced a great deal of misfortune during

the last ten years, while Teresa has experienced an abundance of wonderful life events during the same ten years. However, Sandra appears to be a much happier person than Teresa. Which of the following is the best explanation for these two women's emotional states? a. Although Teresa does not appear to be extremely happy on the outside, she must really be very happy since it is one's life events that determine subjective well­being. b. Sandra is in denial regarding her "sad" situation and will suffer depression and poor health in the future. c. Sandra must be good at negotiating and managing these unhappy events in her life. d. Teresa most likely has a mental illness that is preventing her from experiencing happiness.

When Jude is practicing on his own, he can run the 400 meters in 60 seconds. However, when he is running against a competitor he is able to run the 400 meters in just over 56 seconds. The improvement in Jude's performance when he runs against a competitor is consistent with the concept of:

a. social facilitation b. social interference c. normative social influence d. a self-serving bias