MLLONDONExtroverts are happier than introverts because of a more effective 'desire' system', researchers have discovered. Previous theories had claimed the the effect was caused by a more effective pleasure system - but that has now been discounted.To make their discovery, researchers analysed over 1,300 people, tracking their response to 14,000 activities. Extroverts, because of their active nature, are more likely to seek and spend more time on rewarding activities,' the researchers said in the journal. 'When they do so, they also experience a higher boost in momentary happiness as compared to their introverted counterparts. 'This partly explains the direct relationship between extraversion and momentary happiness.'Their first finding was that extraverts reported more happiness than introverts during what the researchers defined as 'rewarding' activities that take effort - such as sports and exercise, and financially rewarding work tasks. In contrast, they found there was no difference in extraverts’ and introverts’ happiness during merely low effort, low importance 'pleasurable, hedonic' activities, such as watching TV, listening to music, relaxing, and shopping.However, one exception to this pattern was reading – surprisingly perhaps, extroverts appeared to derive more enjoyment from this activity than introverts. The researchers say this could be because reading isn’t always just for pleasure, but can also be completed in pursuit of a reward, such as to pass a course.'Multilevel results confirm that extraverts (versus introverts) experience a higher boost in momentary happiness when spending time on rewarding – but not pleasurable – activities, especially when rewarding activities are executed with others. 'These processes partly explain why extroverts are happier in the moment.'The researchers also said extroverts experience a bigger happiness boost than introverts when they perform rewarding activities with other people, rather than alone - and say they tend to have more social contact during their daily activities.This news was published in The Nation newspaper. Read complete newspaper of 15-Mar-2014 here.