Accidental Injuries

Accidental injuries (also called unintentional injuries) are a significant public health problem in the United States. Unintentional injuries accounted for 97,860 deaths in 1999 and 40.4 million emergency department visits in 2000. By a very large margin, unintentional injuries are the leading cause of death for individuals between the ages of 1 and 34 years. In 1999, unintentional injuries accounted for 43 percent of deaths in the 1- to 24-year-old age group, with deaths from accidents peaking between 15 and 19 years of age. Males are more susceptible to unintentional injuries than are females. For males, unintentional injuries rank as the fourth leading cause of death, whereas for females, unintentional injuries are the seventh leading cause of death. Unintentional injuries are caused most commonly by motor vehicles, followed in number by falls, poisoning, drowning, suffocation (especially for infants), and fire/burns. Billions of dollars are spent each year in the United States dealing with the problem of unintentional injuries.

Despite the growing national concern over reducing unintentional injuries, the underlying behavioral causes of such injuries have received relatively little attention from injury researchers. However, without a clear understanding of the behaviors that lead to accidents, it is difficult to know who or what to target for intervention. For example, although all children would benefit from wearing bicycle helmets, it is particularly important to increase helmet use among children who routinely engage in behaviors that put them at risk for bicycling crashes. Thus, understanding the behavioral causes of unintentional injuries is critical for designing effective interventions.

Personality Factors and Injury Proneness

Personality traits are frequently implicated as a major contributor to injury risk, especially during childhood and adolescence. In the first investigation to examine links between children’s personality traits and injury risk, researchers examined the records of San Francisco Bay area children aged 4 to 18 years who had been enrolled in a particular medical insurance plan. Using insurance records, they divided children into three groups of high, medium, or low annual injury rates. They found that children who experienced a high number of injuries were rated by their mothers as more hyperactive, impulsive, aggressive, extraverted, independent, curious, daring, and careless. Other research has also linked personality traits with more minor, everyday injuries. Specifically, 8-year-olds whose parents described them as highly active, impulsive, and undercontrolled had more severe day-to-day injuries.

Several studies following the same children over a long period of time have also found a link between personality traits and unintentional injuries. In one study, more than 10,000 children were tested at age 5 years and again at age 10 years. An important finding was that high activity and aggression levels were linked to higher injury rates. Likewise, a Finnish study that tested individuals at ages 8, 14, and 27 years revealed that boys who were aggressive at ages 8 and 14 years had experienced more injuries by age 27 years. Another study examined how impulsivity and self-control at age 4 years were related to injury risk at age 6 years. Children who were impulsive and undercontrolled at age 4 years had a history of injuries requiring medical attention at age 6 years. Thus, it appears that early manifestations of impulsivity, noncompliance, and high activity level are predictive of later injury risk.

Research on children with clinical diagnoses has yielded similar results and generally indicates that children with externalizing disorders such as Attention Deficit/Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD) are more at risk for injury. One study revealed that parents who described their children as hyperactive also described their children as more at risk for injury. An investigation of nearly 1,000 children from two hospitals in South Wales from birth through age 5 years revealed that children with serious discipline problems had more injuries. Another study found that children with ADHD anticipated less severe consequences following risky behaviors than did non-ADHD control children. Thus, clinical studies suggest that injury-prone children are more aggressive, overactive, and poorly disciplined.

Together, these studies suggest that impulsive and under-controlled children are more at risk for injury. How might such traits put children at risk for injury? Certain personality characteristics may lead children to seek out some situations and avoid others. For example, highly active and approach-oriented children may seek out new and unfamiliar situations. Novel situations may lead to injuries because such situations force children to react to potentially unforeseen, dangerous problems. Thus, by seeking out some situations, children may put themselves at greater risk of injury.

Cognitive Factors and Injury Proneness

One cognitive factor that has been recently linked to injury risk is overestimation of physical ability. More specifically, errors in judging the relation between ones physical abilities and the demands of the situation may contribute to injury risk. For example, to bicycle across a road safely, children must evaluate their own level of bicycling skill in relation to the demands of the situation. In the case where cross-traffic does not stop, children must wait for a sufficient gap between vehicles before crossing. To determine whether the gap between two vehicles affords safe crossing, children must accurately judge the size of the gap in relation to the time it will take them to bicycle across the road. If children overestimate how quickly they can bicycle across the road, they may choose a gap that is too short for safe crossing. Such errors in judgment may lead to severe injury if the child is hit by an oncoming car.

Several studies have examined children’s ability to judge traffic gaps. In one study, researchers developed a road-crossing task to assess age changes in children’s ability to accurately judge whether traffic gaps afford safe crossing. Five- to 10-year-old children crossed a “pretend” road set up directly parallel to an actual road. Children watched the cars on the actual road and crossed the pretend road when they felt that they could safely reach the other side. Although children generally were cautious, they occasionally accepted gaps that were too short. In addition, a higher proportion of younger than older children made such errors. These findings suggest that younger children are more likely to overestimate their ability to walk through traffic gaps.

The finding that children sometimes overestimate their ability to cross roads is consistent with other studies showing that children also overestimate other physical abilities. For example, one study found that 9- and 12-year-old boys overestimated the height of the stairs they could climb. Other studies have consistently shown that 6- and 8-year-olds overestimate their reaching and stepping abilities. Moreover, 6-year-olds who overestimate their physical abilities tend to have more unintentional injuries requiring medical attention. Thus, it appears that overestimation of ability may be a risk factor for unintentional injuries during childhood.

The role that overestimation of ability plays in unsafe behavior has also been investigated in studies of young automobile drivers. In one study, researchers found that young male drivers perceived their chances of having a collision to be significantly lower than those of both their male peers and older male drivers. Older male drivers, on the other hand, saw their chances of a collision as comparable to those of their male peers and less than those of younger male drivers. Another study revealed that young males rated their driving abilities as being the same as those of older males, but saw their peers as being at greater risk and having poorer driving abilities than themselves. The discrepancy between young drivers’ perceived and actual driving ability may result in a misperception of danger, and hence a greater likelihood of automobile collisions.

Taken together, these results suggest that children and adolescents may perceive the boundary between actions that are within and beyond their ability as fuzzy. Moreover, when faced with uncertainty, children and adolescents are more likely to overestimate than underestimate their abilities. Thus, errors in judgment appear to be another risk factor for unintentional injury.


Unintentional injuries are the leading cause of death for individuals up to age 34 years. Understanding the behavioral factors that put people at risk for injury is critical for designing interventions to prevent such injuries. Recent studies show that both personality and cognitive factors lead to risky behaviors, particularly during childhood and adolescence. Targeting intervention efforts at individuals who are the most likely to engage in risky behaviors is one promising avenue for preventing unintentional injuries.


  1. Bijur, P., Golding, J., Haslum, M., & Kurzon, M. (1988). Behavioral predictors of injury in school-age children. American Journal of Diseases of Children, 142, 1307-1312.
  2. Bijur, P. E., Stewart-Brown, S., & Butler, N. (1986). Child behavior and accidental injury in 11,966 preschool children. American Journal of Diseases of Children, 140, 487-492.
  3. Davidson, L. L. (1987). Hyperactivity, antisocial behavior, and childhood injury: A critical analysis of the literature. Developmental and Behavioral Pediatrics, 8, 335-340.
  4. Farmer, J. E., & Peterson, L. (1995). Injury risk factors in children with Attention Deficit Hyperactivity Disorder. Health Psychology, 14, 325-332.
  5. Fingerhut, L. A., & Warner, M. (1997). Injury Chartbook. Health, United States 1996-97. Hyattsville, MD: National Center for Health Statistics.
  6. Finn, P., & Bragg, B. W. (1986). Perception of the risk of an accident by young and older drivers. Accident Analysis and Prevention, 18, 289-298.
  7. Gayton, W. G., Bailey, C, Wagner, A., & Hardesty, V. A. (1986). Relationship between childhood hyperactivity and accident proneness. Perceptual and Motor Skills, 63, 801-802.
  8. Institute of Medicine. (1999). Reducing the burden of injury. Washington, DC: National Academy Press.
  9. Lee, D. N., Young, D. S., & McLaughlin, C. M. (1984). A roadside simulation of road crossing for children. Ergonomics, 12, 1271-1281.
  10. Mathews, M. L., & Moran, A. R. (1986). Age differences in male drivers’ perception of accident risk: The role of perceived driving ability. Accident Analysis and Prevention, 18, 299-313.
  11. Manheimer, D., & Mellinger, G. (1967). Personality characteristics of the child accident repeater. Child Development, 38, 491-514.
  12. McKenzie, B. E., & Forbes, C. (1992). Does vision guide stair climbing? A developmental study. Australian Journal of Psychology, 44, 177-183.
  13. National Center for Health Statistics. Latest statistics on injuries in the United States. Available from
  14. Plumert, J. M. (1995). Relations between children’s overestimation of their physical abilities and accident proneness. Developmental Psychology, 31, 866-876.
  15. Plumert, J. M., & Schwebel, D. C. (1997). Social and temperamental influences on children’s overestimation of their physical abilities: Links to accident proneness. Journal of Experimental Child Psychology, 67, 317-337.
  16. Pulkkinen, L. (1995). Behavioral precursors to accidents and resulting physical impairment. Child Development, 66, 1660-1679.
  17. Rivara, F. P., & Aitken, M. (1998). Prevention of injuries to children and adolescents. Advances in Pediatrics, 45, 37-72.
  18. Schwebel, D. C, & Plumert, J. M. (1999). Longitudinal and concurrent relations between temperament, ability estimation, and injury proneness. Child Development, 70, 700-712.

Back to Health Psychology.