Researchers say there are several factors that may explain the link between optimism and longer life.

The relationship between optimism, eye gaze and negative images of climate change.

Between optimism and pessimism there is something called reality.

The connection between economics and optimism was clearly demonstrated by the survey.

The popular feeling shifts between guarded optimism and outright pessimism.

Seemingly teetering on the knife's edge between optimism and despair.

The opening lead was often a heart, and South had to choose between optimism and pessimism.

"We're finally brought to making the distinction between hope and optimism," he said.

It's a morning split between deep cynicism and pugnacious optimism.

There is much debate about the relationship between explanatory style and optimism.