[belorn]

There are an alternative interpretation of the same data. The rat park may provide protection against addition, while the rat cage makes the rats more vulnerable to addition.

This model is often use with illnesses such as chronic stress, depression and ptsd. A "rat park" has many major health benefits, and aspect of it is measured with organ donations in order to determine which patients has the highest probability of surviving.

A way to see it is that in order for a negative outcome you need three things to be true. Be exposed to a trigger, while being vulnerable, and lacking protection.