As a group, older adults report positive affective lives. The extent to which there are subgroups of older adults whose moods are less positive, however, is unclear. Our aim in the present study was to identify and characterize different subgroups of adults who exhibit distinct trajectories of mood change across a relatively short time period.…

Normative adult age-related decrements are well documented for many diverse forms of effortful cognitive processing. However, it is currently unclear whether each of these decrements reflects a distinct and independent developmental phenomenon, or, in part, a more global phenomenon. A number of studies have recently been published that show…

The purpose of this dissertation is to examine long term changes in the overnight backcountry hiker population at Grand Canyon National Park (GCNP) between 1984 and 2004. Longitudinal studies of visitor behavior in wildland recreation settings have been relatively rare but offer great potential for the improvement of management, clarification of…

The technological complexity and richness of a child's environment today is far beyond what any adults today experienced when they were growing up. For example, no adult today knows what it is like to be a four-year-old using his or her first iPhone app or Webkinz account. Therefore, we seek ways to understand what children need in today's new…