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.     

EFFECTS OF MEMORY AIDS ON THE DYADIC CONVERSATIONS OF INDIVIDUALS WITH DEMENTIA

The effects of a prosthetic memory aid on the conversational content and social skills of dyads with dementia were evaluated. Six individuals with moderate to severe dementia served as either subject or partner in dyads during 5-min conversational probes conducted three times per week in daycare and nursing-home settings. During phases when a memory aid, consisting of personally relevant picture and sentence stimuli, was available, most subjects used their own aid to improve the quality of conversations by increasing the frequency of on-topic statements, diminishing nonproductive utterances, lengthening their conversational turn, and/or increasing the frequency of turns taken. Most partners demonstrated awareness of social discourse conventions by appropriately relinquishing conversational dominance, decreasing both content and nonproductive utterances, and increasing acknowledging or affirmative comments when subjects used memory aids. Naive judges' ratings of aided and unaided conversational samples on seven conversational dimensions reflected differences in perceptions of significant improvement as a function of the conversational discourse style of each dyad.     

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.     

A maximum likelihood method for latent class regression involving a censored dependent variable

The standard tobit or censored regression model is typically utilized for regression analysis when the dependent variable is censored. This model is generalized by developing a conditional mixture, maximum likelihood method for latent class censored regression. The proposed method simultaneously estimates separate regression functions and subject membership in K latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The proposed method is illustrated via a consumer psychology application.     

Parental functioning and children's adjustment in families of divorce: A prospective study

This paper prospectively examined relations between marital status, predivorce parenting practices, and children's adjustment, using data from the New York Longitudinal Study (NYLS). Prospective analyses of children's predivorce adjustment indicated that neither boys nor girls showed more problematic behavior prior to parental separation, and only boys had more difficulties after divorce. However, parents of to-be-divorced families reported more difficulties in childcare practices before divorce than did parents of always-married families. Parenting difficulties in to-be-divorced families were found consistently for boys but not for girls. Results suggest that the difficulties found among boys after divorce may be linked with parenting problems that begin before divorce.The authors are indebted to Alexander Thomas and Stella Chess, the original investigators of the project. We also would like to thank Jacqueline and Richard Lerner, and the John D. and Catherine MacArthur Foundation for their efforts in preserving this data base.     

The Sum and Substance of It: The Appreciation of Mass and Count Quantifiers in Parkinson′s Disease

We performed three experiments in order to determine whether patients with Parkinson′s disease (PD) have a sentence comprehension impairment. In the first experiment, we found that nondemented PD patients were impaired at matching a short sentence containing a mass or count quantifier (e.g., "Point to the jar with many") with one of four pictures. Patients erred by pointing to the incorrect mass or count type of substance, but pointed correctly to the large or small amount of a substance in the picture. In the second experiment, we asked the same PD patients to judge short sentences containing mass or count nouns modified by mass or count adjectives (e.g., *"The glass contains many milk"). PD patients were significantly impaired at detecting errors in the agreement between a noun and a quantifying adjective and errors in the appropriate use of the plural associated with a noun. A sentence completion task was performed in order to determine whether patients impaired on both sentence-picture matching and sentence judgment tasks are also compromised in their expression of quantifiers. Some patients impaired on both tasks also had difficulty expressing quantifiers, and it is these patients who may have difficulty performing grammatical computations. Other patients were selectively impaired in their sentence-picture matching or their sentence judgments, suggesting a performance deficit concerned with a particular task. We conclude that sentence comprehension impairments in PD are multifactorial in nature.     

Child and adolescent psychopathology research: Problems and prospects for the 1990s

In November 1990 the National Institute of Mental Health (NIMH) convened a special conference of over 100 scientists and leaders to outline specific strategies and research initiatives that should be developed to implement the recently released National Plan for Research on Child and Adolescent Mental Disorders.Participants included journal editors, educators from psychology and psychiatry, representatives from private foundations, and leaders of research program areas in public funding agencies. Critical knowledge gaps were identified in five areas of child and adolescent psychopathology, including depression, attention deficit hyperactivity disorder, conduct disorder, the anxiety disorders, and the developmental disorders. For each of these areas, special emphasis was placed on developing new ideas and obtaining critical input from other areas of investigation. This report summarizes the identified research gaps and recommends research initiatives to implement the National Plan, as outlined by the conference participants.     

Hypermnesia in free recall and cued recall

In three experiments, categorized lists and both free recall and cued recall tests were used to examine hypermnesia. In Experiment 1, materials were drawn from obvious and nonobvious categories in an attempt to vary the amount of relational processing at encoding. The study materials in Experiment 2 consisted of a long word list that comprised several exemplars from each of a number of common categories. In Experiment 3, a single exemplar was drawn from each of 45 categories. In each experiment, similar magnitudes of hypermnesia were obtained on free and cued recall tests. Examination of the specific items recalled across tests indicated that similar processes underlie the hypermnesic effect for both test conditions. Implications of the results for extant accounts of the hypermnesic effect are discussed. It is concluded that the dynamics of retrieval processes change in a systematic fashion across repeated tests and the retention interval following study and that an adequate account of the nature of these changes in retrieval dynamics is essential to our understanding of hypermnesia and related phenomena.