Mind games for self-improvement fall into two main categories. There are mental exercises and puzzles to maintain or improve the actual working of the brain.Mental exercises can be done through simple socializing. Social interaction engages in many facets of cognitive thinking and can facilitate cognitive functioning. Cartwright and Zander noted that if an alien was visiting Earth for the first time, they would be surprised by the amount of social contact humans make. Caring for one another and growing up in a group setting (family) shows a certain degree of interdependence that shows deep phylogenetic roots. However, this social contact is declining in the United States. Face-to-face interaction is getting more and more sparse. Family and friend visits, including dinners, are not as common. The amount of social contact a person receives can greatly affect their mental health. A preference for being with others has a high correlation with well-being and with mental long-term and short-term effects on performance.