In the 1940s Abraham Maslow wrote a short paper (just 34 pages) about what motivates us. It has become famous as Maslow’s Hierarchy of Needs. This book is that paper.
It requires some studying, and I needed a dictionary at hand as it is quite an academic read, but if you are interested in the theory, it is really helpful in providing some more depth to Maslow’s thoughts.
Maslow suggested that we are motivated to take action by different needs. He said that those needs are not all equal, and that in fact there is a Hierarchy.
He describes FIVE (although later work has increased this to seven) types of need:
1) Physiological (Food, water, sleep etc)
2) Safety (Housing, protection from violence and crime, Health.
3) Love and belongingness (having loving friends, family, and partners)
4) Esteem (feeling respected and admired by others, and having self-respect)
5) Self-Actualisation (Doing that which you feel is your “purpose” – e.g. creating music or art, helping others, teaching)
Having described these 5 levels, Maslow suggests that if you are severely lacking in a need at a lower lever (e.g. if you are starving), then you are almost entirely motivated by trying to find food. You would find it very difficult to do things which only satisfy a higher-level need – e.g. socialising with a group of aquaintenances.
It also explains why you might find it difficult to be a good team member at work (Belongingness), if you are worried about your house being repossessed (a Safety need).
Many businesses have now taken this on board to consider how they can motivate their employees more. Simply providing a salary which will help with their need for food, housing etc. may not be enough. You might also need to provide opportunities for socialising, gaining respect from team members by asking them to speak at meetings etc.
If you want to understand a bit more about what drives people, and how you can help motivate people, this is worth a read.