What structure is described in your text as the "gray matter" that forms the top portion of the brain?

Based on Mary Ainsworth's studies, ________ children did not care if the mother left the room, made little effort to seek contact with her on her return, and treated a stranger about the same way as the mother

a. avoidant b. securely attached c. anxious d. ambivalent

Julie posts an ad in the newspaper and quickly obtains a sample of 1st -time parents. Which of

the following statements is most true regarding this volunteer or self-selected sample? A) This method is so biased that she will not be able to publish the results of the study. B) The participants will be better educated and more intelligent that parents that did not volunteer. C) The participants will be similar in terms of social class than people that do not volunteer. D) This method is known as stratified random sampling.