After reading the actual underlying study the article headline seems bogus. The study simply found an association between the amount/quality of time spent with

After reading the actual underlying study the article headline seems bogus. The study simply found an association between the amount/quality of time spent with a person and closeness of the friendship. There's nothing in the study design that allows us to distinguish whether spending time together creates friendships or if spending time together is only an indicator of a friendship. Could simply mean that feeling close to someone leads people to spend more time together.