Genetic and Environmental Effects on Openness to Experience, Agreeableness, and Conscientiousness: An Adoption/Twin Study

ABSTRACT Previous research has indicated that extraversion and neuroticism are substantially affected both by genotype and environment. This study assesses genetic and environmental influences on the other three components of the five-factor model of personality: Openness to Experience, Agreeableness, and Conscientiousness. An abbreviated version of the NEO Personality Inventory (NEO-PI) was administered to 82 pairs of identical twins and 171 pairs of fraternal twins reared apart and 132 pairs of identical twins and 167 pairs of fraternal twins reared together. Estimates of genetic and environmental effects for Openness and Conscientiousness were similar to those found in other studies of personality: Genetic influence was substantial and there was little evidence of shared rearing environment. Results for Agreeableness were different: Genetic influence accounted for only 12% of the variance and shared rearing environment accounted for 21% of the variance. Few significant gender or age differences for genetic and environmental parameters were found in model-fitting analyses.     

The use of subtle items in detecting deception

When subjects attempt to fake psychopathology on the MMPI, scores on subtle subscales tend to be lower than those of nonfaking subjects. Our study hypothesized that this paradox comes about because the subtle subscales have no predictive validity, but their face validity for psychopathology is the opposite of the keyed direction for psychopathology. Subjects who attempt to fake psychopathology do so on the basis of item content and thus achieve lower rather than higher scores. Three groups of 80 undergraduates took the MMPI under regular, faking-good, or faking-bad instructions. As expected, faking-bad subjects scored significantly lower than regular subjects on the 100 most subtle items, and this was due to their responses to those. 73 of the items whose face validity was misleading. The results are consistent with other work showing valid uses of subtle items in detecting deception.     

Morale and Job Satisfaction Among Nurses: What Can Hospitals Do?

In an attempt to account for morale and job satisfaction among 314 nurses, this study investigated the influence of work-related and interpersonal variables. Morale on the unit was directly related to supervisor support, co-worker relationships, and work recognition. Personal morale was accounted for by recognition, physical environment, the job itself, and pay. Job satisfaction was predicted by personal morale, work commitment, job clarity, work pressure, and innovation. Suggestions for improving nurse morale and job satisfaction are made.     

The substitutability of reinforcers

Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included.     

Delay reduction: current status.

Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement.     

TEMPORAL CONTROL ON INTERVAL SCHEDULES: WHAT DETERMINES THE POSTREINFORCEMENT PAUSE?

On fixed-interval or response-initiated delay schedules of reinforcement, the average pause following food presentation is proportional to the interfood interval. Moreover, when a number of intervals of different durations occur in a programmed cyclic series, postreinforcement pauses track the changes in interval value. What controls the duration of postreinforcement pauses under these conditions? Staddon, Wynne, and Higa (1991), in their linear waiting model, propose control by the preceding interfood interval. Another possibility is that delay to reinforcement, signaled by a key peck and/or stimulus change, determines the subsequent pause. The experiments reported here examined the role of these two possible time markers by studying the performance of pigeons under a chained cyclic fixed-interval procedure. The data support the linear waiting model, but suggest that more than the immediately preceding interfood interval plays a role in temporal control.     

How much can people really change?

The basic purpose of pastoral counseling, and counseling in general, is to help people change. Therefore, it's critically important to understand the nature of change and to have realistic expectations with respect to how much people can change. To expect too little change can lead to underachievement and despair, whereas to expect too much change can cause needless frustration and an abiding sense of failure. This article discusses behavioral change, its potential and its limits, from the point of view of genetic potential and offers some specific pastoral implications.     

The prediction of adjustment at age 7 from activity level at age 5

One-hundred and ninety-two children (equally split between boys and girls) were studied when they were 5 years old in two settings, school and home. The children were observed in playgroups and at home, and were rated on activity level by their parents on the Rothbart Child Behavior Questionnaire. At age 7, the children were tested in our laboratory on the Harter Test of Perceived Competence and on an achievement task, and parents filled out the Child Behavior Checklist, the Child Behavior Questionnaire, and the Conners Parent Rating Scale. Home observations of activity level were significantly related to parent ratings of activity level, but not to school observations. Activity level at age 5 was related to parents' ratings of aggression and hyperactivity and to girls' learning problems at age 7. Activity level was not related to the children's self-perceived competence, but mothers' rating of high activity level at age 5 was related to low reading comprehension at age 7.Preparation of this paper was supported in part by the Center for Research for Mothers and Children, NICHD, U.S. PHS grant HD 19739 to Beverly I. Fagot.