The growth rate in height reaches a peak at age ______ in girls.

Which of the following is true of sampling behavior with tasks?

a. Sampling behavior with tasks may not really sample the behavior of interest. b. Sampling behavior with tasks can be used to observe behavior directly. c. Sampling behavior with tasks isn't a popular method because it isn't convenient to use. d. Sampling behavior with tasks might lead some children to provide socially acceptable answers.

According to research on the recognition of emotions, which emotion would be most difficult to distinguish from happiness?

a. surprise b. sadness c. anger d. disgust