Two experiments explored whether children's correct answers to counterfactual and future hypothetical questions were based on an understanding of possibilities. Children played a game in which a toy mouse could run down either 1 of 2 slides. Children found it difficult to mark physically both possible outcomes, compared to reporting a single hypothetical future event, "What if next time he goes the other way ..." (Experiment 1: 3-4-year-olds and 4-5-year-olds), or a single counterfactual event, "What if he had gone the other way ...?" (Experiment 2: 3-4-year-olds and 5-6-year-olds). An open counterfactual question, "Could he have gone anywhere else?," which required thinking about the counterfactual as an alternative possibility, was also relatively difficult.

Keysar et al. (Keysar, Barr, Balin, & Brauner, 2000; Keysar, Lin, & Barr, 2003) report that adults frequently failed to use their conceptual competence for theory of mind (ToM) in an online communication game where they needed to take account of a speaker's perspective. The current research reports 3 experiments investigating the cognitive processes contributing to adults' errors. In Experiments 1 and 2 the frequency of adults' failure to use ToM was unaffected by perspective switching. In Experiment 3 adults made more errors when interpreting instructions according to the speaker's perspective than according to an arbitrary rule. We suggest that adults are efficient at switching perspectives, but that actually using what another person knows to interpret what they say is relatively inefficient, giving rise to egocentric errors during communication.

Background Agriculture is one of the most hazardous industries in the US. Methods We reviewed MEDLINE and NIOSHTIC to identify English‐language studies addressing occupational injury among agricultural populations, focusing on North America. Additional references were identified from the reference lists of identified studies and from contacts with experts in the field. Results U.S. data indicate up to approximately 780 deaths and 140,000 cases of nonfatal disabling injuries in 1998. Risk of agricultural injuries is approximately 5‐10/100 persons per year, but is higher in certain risk groups, such as males and cattle workers. Falls, machinery, and animals are among the most common causes. Unique features of the agricultural workplace and exposed population combine to increase risk and hinder accurate measurement. These features include a wide range of activities, hazards, and dispersed work places in agriculture; a seasonal hired work force that often has brief tenure, poor English skills, and a distrust of officialdom; and a history of exemption regarding occupational health and safety regulations. Conclusions Research in agricultural injury should include epidemiologic study of risk factors and evaluation of interventions. Although only limited data are available documenting efficacy of specific preventive approaches, prevention should focus on engineering controls, regulatory approaches, and education. Am. J. Ind. Med. 38:463–480, 2000. © 2000 Wiley‐Liss, Inc.

Agricultural injury experience in this cohort is comparable to that of agricultural workers in other U.S. settings. Increased risk among women paid piece-rate suggests further study and potential policy changes regarding payment regimens. Heterogeneity of injury in this population presents a major prevention challenge. In view of high frequency of strain and sprain injuries, ergonomic interventions deserve further study.

Cognitive training has been shown to improve executive functions (EFs) in middle childhood and adulthood. However, fewer studies have targeted the preschool years—a time when EFs undergo rapid development. The present study tested the effects of a short four session EF training program in 54 four-year-olds. The training group significantly improved their working memory from pre-training relative to an active control group. Notably, this effect extended to a task sharing few surface features with the trained tasks, and continued to be apparent 3 months later. In addition, the benefits of training extended to a measure of mathematical reasoning 3 months later, indicating that training EFs during the preschool years has the potential to convey benefits that are both long-lasting and wide-ranging.