The effect of environment on visual cliff performance in the Mongolian gerbil

Depth perception in the Mongolian gerbil was investigated as a function of age and environment. Thirty-two gerbils were raised in either a cliff or flat environment, and half the gerbils in each condition were tested on the visual cliff from 21 to 57 days of age. All gerbils were tested at 60–61 days on a standard visual cliff, a barrier cliff which prevented movement along the centerboard, and a jumping platform. While the gerbils did not display a preference for the shallow side when tested at 21 days, those living in a cliff environment showed rapid acquisition of such a preference, whereas those living in a flat environment did not. By 60–61 days, however, all gerbils demonstrated a strong preference for the shallow side on both versions of the visual cliff, regardless of environment or pretesting experience.     

Toward an empirical subclassification of “learning disabilitiesℍ: A psychophysiological comparison of “hyperactiveℍ and “nonhyperactiveℍ subgroups

The diagnostic category of learning disabilities is a heterogeneous one, but few empirical attempts have been made to distinguish subgroups. Recent research, however, suggests that it may be meaningful to discriminate between hyperactive and nonhyperactive learning-disabled children. In the present study, 21 learning-disabled children identified as hyperactive through teacher nominations and ratings were compared to 15 learning-disabled children identified as nonhyperactive in the same manner. The two groups differed on rated behavior, birth order, amount of prescribed stimulant medication, amount of psychosocial stress, and Verbal, Performance, and Full Scale WISC-R IQ scores. They did not differ, however, on several demographic variables, the number of perinatal complications, reading achievement, and a number of tonic and phasic measures of autonomie activity. These findings support the distinction between hyperactive and nonhyperactive subgroups of learning-disabled children, but suggest that the two subgroups may have a similar biological substrate.We wish to express our sincere appreciation to Douglas Carmichael, Martha Stewart, Kay Richmond, and the teachers of Clarke County for their kind and sophisticated assistance, and to David Coleman and David Hammer for their technical assistance.     

Design and use of a U.S. census data computer laboratory for teaching undergraduate research methods

This paper discusses the design and development of an interdisciplinary social science computer laboratory for teaching undergraduate research methods courses and research components of applied and theoretical courses. The U.S. Census of the Population, a database commonly used in all of the social sciences, is used in order to give students research experience and to avoid ethical problems involved in working with animal and human subjects in an undergraduate course. Some issues in laboratory design and required changes in teaching methods are discussed.     

Examining Self-Concealment within the Framework of Psychological Inflexibility and Mindfulness: A Preliminary Cross-Sectional Investigation

Although self-concealment has been a central topic in the field of personality and applied psychologies, it remains somewhat unclear how it should be conceptualized. The present study investigated self-concealment within the framework of psychological inflexibility and mindfulness, two major emotion/behavior regulation processes integrated into contemporary cognitive behavioral models of behavioral health. One-thousand sixty college undergraduates (77 % female; n = 816) completed a web-based survey that included the measures of interest. Results revealed that psychological inflexibility was positively and uniquely associated with self-concealment. The association between mindfulness and self-concealment was moderated by gender; higher levels of self-concealment predicted lower levels of mindfulness for women only and were associated with sexual-minority men, but self-concealment did not vary for women as a function of sexual orientation status. Additional results and future directions are also discussed.     

Selecting one of two regular sound sequences: perceptual and motor effects of tempo

This study assessed the influence of tempo on selecting a sound sequence. In Exp. 1, synchronization with one of the two regular subsequences in a complex sequence was measured. 30 participants indicated a preference for the fastest subsequence when subsequences were in a slow tempo range (> or = 500 msec. IOI), and with the slower subsequence when they were in the fast tempo range (< or = 300 msec. IOI). These results were replicated using a perceptual task (Exp. 2 and 3) in which the 30 listeners had to detect a temporal irregularity in one of the two subsequences. Detection was better when the temporal irregularity was in the fastest subsequence than in the slowest one when the complex sequence was in a slow tempo range (> or = 500 msec. IOI) and the reverse was obtained when the complex sequence was in a fast tempo range (< or = 180 msec. IOI). These results have implications for design of auditory alarms.     

College Students’ Video Game Participation and Perceptions: Gender Differences and Implications

As growing numbers of youth in the United States play video games, potential effects of game playing are being considered. We focused on gender-related aspects of gaming in a study of 206 college students. Men were significantly more likely than women to play video games two or more hours a week and to indicate that video game playing interfered with sleeping and with class preparation. A greater proportion of women than men complained about the amount of time their significant other played video games. Participants rated female video game characters as significantly more helpless and sexually provocative than male characters and as less likely to be strong and aggressive. Gender differences in participation and character portrayals potentially impact the lives of youth in a variety of ways.     

Tie strength and family formation: Which personal relationships are influential?

On the basis of the analysis of qualitative interviews in Western Germany, it has been argued that personal relationships have a strong impact on individuals' family formation processes and childbearing intentions. Persons who influence individuals' childbearing choices were identified. Strong ties, such as among core family members (i.e., parents and siblings), are an important contributing factor, but the authors are also able to show that weak ties, such as those among colleagues and acquaintances, need to be considered when examining social influence on family formation processes. Apart from single network partners, influential groups of persons have been identified. Such groups serve as a comparative standard regarding the timing of having one's first child and subsequent children.