By Annie Krall
Medill Reports

Starbucks has learned how to make customers keep coming back for more thanks to their rewards program.

And they’re not alone.

Thousands and thousands of businesses use rewards programs to draw customers in and keep them loyal. But why is potentially getting the next stamp or another level up so enjoyable to us?

Talia Lerner, a neurobiologist at Northwestern University’s Feinberg School of Medicine, and her team of researchers are trying to answer that question and many more. Using mice as test subjects they are analyzing the neurological pathways that make compulsive behaviors so difficult to stop, especially when it comes to alcoholism or obsessive-compulsive disorder (OCD).