Washington: People are generally happy with their lives, including even those with physical or mental disabilities and having less money, according to a new survey.

The survey conducted in the United States and around the world reviewed several studies on autobiographical memory and happiness and found that human memory is biased toward happiness and mild depression can disrupt this bias for good over bad.

In their article, W Richard Walker of Winston-Salem State University and colleagues found two causes for people's recollection of the past to be positively biased. The first cause seems to be due to the simple fact that pleasant events do outnumber unpleasant events, because people seek out positive experiences and avoid negative ones.

Across 12 studies conducted by five different research teams, people of different racial and ethnic backgrounds and participants who ranged in age from late teens to early 50s consistently reported experiencing more positive events in their lives than negative ones.

The other process at work involves the memory system treating pleasant emotions differently from unpleasant emotions. Seven studies reviewed by the researchers provide support for a fading affect for negative emotions.

Pleasant emotions have been found to fade more slowly from our memory than unpleasant emotions. One mechanism for this uneven fading may involve a process known as minimisation. In order to return to our normal level of happiness, we try to minimise the impact of life events. This minimisation process – which occurs biologically, cognitively and socially – is usually stronger for negative events than for positive events.

"This implies that there is a tendency to deaden the emotional impact of negative events relative to the impact of positive events. Such deadening occurs directly because people are motivated to view their life events in a relatively positive light," said Dr Walker.

Of course, life is not pleasant for everyone. Among those with mild depression, unpleasant and pleasant emotions tend to fade evenly. The researchers found increased levels of depression were associated with a greater disruption of the fading affect bias.

ANI