Penny wanted to find out how long it would take her sister Cathy to press a button when she hears a tone. Penny is studying what type of process?

Frank and Joe are 55-year-old monozygotic twins. Since their genes are identical, according to research, how will they age?

They will age identically. They will age very similarly. If one shows minor variations in ability, so will the other. One can show much variation in ability and the other may not.

What does the research in your text suggest is the cost of parenting?

a) About $400,00 b) The loss of privacy c) The loss of freedom d) The loss of personal satisfaction from working