As early as 2 weeks of age, infants show a preference for looking at a photo of their mother as opposed to looking at a photo of a stranger

In Piaget's concrete operational stage, children

A) consider all possible outcomes in a scientific problem. B) develop the capacity for abstract thinking. C) reason with symbols that do not refer to real-world objects. D) transform cognition into logical reasoning.

A serious problem for the use of lithium in treating mania is that

A) lithium can only be used for short periods of time. B) the drug can produce a fatal overdose. C) lithium may not work in up to 50 percent of patients. D) lithium suppresses normal emotions. E) lithium is the least effective of the current drugs used to treat mania.