A study that looks at a group of people periodically over a period of time is known as a __________ study

Ricky's mother tends to scold him when he fights with other children, while Ricky's father encourages him to fight. This type of inconsistent discipline has been linked to

a. internalizing disorders. b. externalizing disorders. c. higher levels of anxiety. d. higher levels of depression.

According to the principle of natural selection, genetic variations become more common over time if they are adaptive in a particular environment

Indicate whether this statement is true or false.