“Email, for example, utilizes all three variable reward types. What subconsciously compels us to check our email? First, there is uncertainty surrounding who might be sending us a message. We have a social obligation to respond to emails and a desire to be seen as agreeable (rewards of the tribe). We may also be curious about what information is in the email. Perhaps something related to our career or business awaits us? Checking email informs us of opportunities or threats to our material possessions and livelihood (rewards of the hunt). Lastly, email is in itself a task — challenging us to sort, categorize and act to eliminate unread messages. We are motivated by the uncertain nature of our fluctuating email count and feel compelled to gain control of our inbox (rewards of the self).”