Introvert

A person who gains energy through low stimulus activities. These activities can include spending time alone, reading, studying, going for a relaxing stroll or jog, etc. Introverts are not necessarily shy and can in fact be very social, provided they have time to recharge afterwards. One defining characteristic seems to be that they feel less reward from highly social situations which is why they can loose energy, feel tired or even overwhelmed when at social events such as parties, concerts, sporting events, etc.