suppose there is a correlation of +0.87 between the length of time a person is in prison and the amount of aggression the person displays on a psychological inventory. this means that spending longer amount of time in prison causes people to become more aggressive is the answer true or false?

A correlation coefficient is a measure of linear association between two variables. If two variables are independent of each other correlation coefficient would be 0.

Normally, correlation coefficient denoted by r can be either positive or negative

Its value always lie between -1 and 1.

Here we are given that there is a correlation of +0.87 between the length of time a person is in prison and the amount of aggression the person displays on a psychological inventory. this means that spending

Since r is positive and also near to 1, we can say there is a strong positive correlation between the length of time a person is in prison and the amount of aggression the person displays on a psychological inventory.

i.e. increase in one variable causes increase in the other

Hence the given statement is true.