In a 2005 paper, Ed Diener, Richard Lucas, and Christie Napa Scollon revisited the concept of the happiness set point. In their view, external events do affect our overall sense of wellbeing—we are not immune to our environment. Nevertheless, over time we do tend to adapt to our circumstances, both good and bad. Moreover, in a 2007 study by Richard Lucas, two fairly large groups of disabled people showed a distinct downturn in their life satisfaction following the onset of their disability, with little to no recovery over time.