A study points out that self-improvement encourages teamwork and initiative.
Competitiveness fosters an ego-oriented climate, that focuses primarily on beating others and is linked with negative peer influences and inappropriate adult behaviours, the study says.
"Our data suggests if coaches want to develop life skills and character in youth, it is important to focus on player self-improvement more so than winning," said researcher Daniel Gould.
"Coaches should create a climate or atmosphere where kids feel cared about, valued, safe and supported," said Gould, who led the study with Larry Lauer, both from Michigan State University Institute for the Study of Youth Sports.
"These positive things should occur while at the same time avoiding the creation of an ego-oriented climate focusing primary attention on comparing themselves to others," Gould was quoted as saying in the journal Psychology of Sport and Exercise.
The study surveyed 239 young urban athletes aged 10 to 19 years who completed the Youth Experiences Scale-2, which measures both positive and negative youth development experiences, a university statement said.
They also completed a caring climate scale, a sport motivation climate scale and measures of the importance their coaches place on psychosocial development.
The results clearly show that the more coaches create caring and task-oriented climates, the more likely important positive developmental gains will occur. Creating an "ego climate" was found to be the single most powerful predictor of negative youth experiences.