Hence they interact with other fermions via electromagnetism and the weak interaction. Leptons do not interact via the strong interaction. Social skill is any skill facilitating interaction and communication with others. Human synergy relates to human interaction and teamwork. Proximity increases the likelihood of social interaction and influence. Situational factors are those that vary between each social interaction. He focused on the interaction and relationship between individuals and parties. Pairing often involves some level of user interaction. This process is mediated by the weak interaction. Persuasion is a form of human interaction. Quokka behavior in response to human interaction has been examined in zoo environments. Iterated rounds often produce novel strategies, which have implications to complex social interaction. The use of a zinc ion in binding leads to a higher affinity interaction. PBL fosters learning by involving students with the interaction of learning materials. It was used for manipulating objects and social interaction.