Which of the following is a neurotransmitter that is used by all motor neurons?

A result of recent gene identification efforts is the

a. firm rejection of gene-environment interaction. b. diminishment of our understanding of the etiology of disorders. c. discovery that a single gene is responsible for most disorders. d. incorporation of gene-environment interaction.

Seven-month-old Gavin seems very content being held by his mother. When the neighbor from across the street comes over to greet Gavin, he turns his head away from the neighbor and starts to cry. What term best explains Gavin's response to the neighbor?

a. Social smile b. Resistant attachment c. Social referencing d. Stranger wariness