Work motivation is a person's internal disposition toward work. To further this, an incentive is the anticipated reward or aversive event available in the environment. While motivation can often be used as a tool to help predict behavior, it varies greatly among individuals and must often be combined with ability and environmental factors to actually influence behavior and performance. Results from a 2012 study, which examined age-related differences in work motivation, suggest a "shift in people's motives" rather than a general decline in motivation with age. That is, it seemed that older employees were less motivated by extrinsically related features of a job, but more by intrinsically rewarding job features. Work motivation is strongly influenced by certain cultural characteristics. Between countries with comparable levels of economic development, collectivist countries tend to have higher levels of work motivation than do countries that tend toward individualism. Similarly measured, higher levels of work motivation can be found in countries that exhibit a long versus a short-term orientation. Also, while national income is not itself a strong predictor of work motivation, indicators that describe a nation's economic strength and stability, such as life expectancy, are. Work motivation decreases as a nation's long-term economic strength increases. Currently work motivation research has explored motivation that may not be consciously driven. This method goal setting is referred to as goal priming.