Icelanders are known for their strong sense of community and lack of social isolation: An OECD survey found that 98% believe they know someone they could rely on in a time of need, higher than in any other industrialised country. Similarly, only 6% reported "rarely" or "never" socialising with others. This high level of social cohesion is attributed to the small size and homogeneity of the population, as well as to a long history of harsh survival in an isolated environment, which reinforced the importance of unity and cooperation.