Surplus and specialization led to the growth of villages. Life became more complex in certain villages as they developed. Extra food and other supplies meant that more people could live together. In this way, surpluses encouraged the growth of villages and population. Surpluses also led to increase trade. People in one village might trade their surplus food for the surplus tools in another village. Workers became more specialized. Potters, Weavers, and other craftpeople often spent years learning their skills. A complex village had a larger population than a simple village, with people living closer together. The larger the population had a greater supply of skills, ideas, and needs. As a results, life in a complex village was more varied and complicated than that in a simple village.