Parental investment, self-control, and sex differences in the expression of adhd

The Gendered Effects of Adult Social Bonds on the Criminal Activities of Probationers

The central question addressed in this article is whether the effects of adult social bonds vary by gender. Contrary to the social control theory, it is argued here that male offenders and female offenders do not respond to the controlling effect of adult social bonds in the same way, because they possess different levels of antisocial tendencies. The authors constructed a two-level hierarchical model using monthly data collected from 125 probationers to evaluate the effects of social bonds and drug use on criminal activities. The findings showed complex patterns. For male probationers, social bonds operated as a strong inhibitor of crime while drug use acted as a moderate facilitator of criminal activities. For female probationers, both social bonds and drug use operated as strong facilitators of criminal behavior. The results support the argument that adult social bonds affect male crime and female crime differently. Implications are presented for future research on adult social bonds as means of crime prevention and control, especially as they are related to gendered patterns of deviant association and lifestyle.

A compensatory role for declarative memory in neurodevelopmental disorders

Most research on neurodevelopmental disorders has focused on their abnormalities. However, what remains intact may also be important. Increasing evidence suggests that declarative memory, a critical learning and memory system in the brain, remains largely functional in a number of neurodevelopmental disorders. Because declarative memory remains functional in these disorders, and because it can learn and retain numerous types of information, functions, and tasks, this system should be able to play compensatory roles for multiple types of impairments across the disorders. Here, we examine this hypothesis for specific language impairment, dyslexia, autism spectrum disorder, Tourette syndrome, and obsessive-compulsive disorder. We lay out specific predictions for the hypothesis and review existing behavioral, electrophysiological, and neuroimaging evidence. Overall, the evidence suggests that declarative memory indeed plays compensatory roles for a range of impairments across all five disorders. Finally, we discuss diagnostic, therapeutic and other implications.

Planning steps forward in development: in girls earlier than in boys

The development of planning ability in children initially aged four and five was examined longitudinally with a retest-interval of 12 months using the Tower of London task. As expected, problems to solve straightforward without mental look-ahead were mastered by most, even the youngest children. Problems demanding look-ahead were more difficult and accuracy improved significantly with age and over time. This development was strongly moderated by sex: In contrast to coeval boys, four year old girls showed an impressive performance enhancement at age five, reaching the performance of six year olds, whereas four year old boys lagged behind and caught up with girls at the age of six, the typical age of school enrollment. This sex-specific development of planning was clearly separated from overall intelligence: young boys showed a steeper increase in raw intelligence scores than girls, whereas in the older groups scores developed similarly. The observed sex differences in planning development are evident even within a narrow time window of twelve months and may relate to differences in maturational trajectories for girls and boys in dorsolateral prefrontal cortex.

Attention deficit/hyperactivity disorder (ADHD) symptoms and digit ratios in a college sample

Diagnosticians recognize three subtypes of attention deficit/hyperactivity disorder (ADHD) if there are developmentally inappropriate levels (six or more symptoms) of Hyperactive-Impulsive behavior, or Inattentive behavior, or both (Combined), respectively. ADHD may partly reflect androgen dysfunction, and an arguable proxy for prenatal androgen exposure is the 2D:4D finger ratio set at least as early as week 9 in the fetus; this is lower in men than in women. We examined the relationship between digit ratios and ADHD symptoms representing the three phenotypes: ADHD/Combined as measured by "summarized" (Rasched) scales, i.e., 1) the short version of the Wender Utah Rating Scale (WURS) and a total symptom list derived from the DSM IV, and the subdivided DSM IV into 2) ADHD/Inattentive and 3) ADHD/Hyperactive-Impulsive inventories, in a sample of European-descent college students (135 female, 52 male) not selected for ADHD. All digit ratios were calculated excluding the thumb. There were significant sex differences for the 2D:4D digit ratios of both hands (RH and LH), and between the RH 3D:4D and between the LH 2D:3D ratio. In females, the more masculine the LH 2D:4D ratio, the more the ADHD/Combined symptoms (both WURS and DSM) and the more the ADHD/Inattentive symptoms and ADHD/Hyperactive-Impulsive symptoms. More masculine ratios also correlated between the total WURS and RH 2D:3D, RH 2D:4D, and LH 2D:3D; and between the inattentive DSM symptoms and LH 2D:5D, and between the ADHD/Hyperactive and Impulsive symptoms and RH 3D:4D.

Attention-deficit hyperactivity disorder and fluctuating asymmetry in another college sample

Attention deficit/hyperactivity disorder (AD/HD) represents a developmental lag that may be reflected in fluctuating asymmetry (FA), i.e., differences from perfect symmetry in traits that display bilateral symmetry. Burton et al. (2003 Am. J. Hum. Biol. 15:601-619) found a statistical trend for FA to increase (as dermatoglyphic index or as total index) as the behavioral measure for AD/HDness (Rasch logit values derived from the Wender Utah Rating Scale, or WURS) increased in males but not in females. The objective here was to do a similar study in an independently collected sample of college students (n = 222; 61 male, 161 female) not selected for AD/HD, looking at FA vs. symptoms for AD/HD based on Rasch versions of responses to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) (Barkley and Murphy 1998 Attention-Deficit Hyperactivity Disorder, New York: Guilford Press, p. 95-96) and the more comparable shortened WURS. FAs were lowest for body and ear height, and highest for eye width and nose width, and ranged from 0.01 +/- 0.001 (mean +/- SE) for foot and ankle widths to 0.13 +/- 0.01 in eye and nose widths for both sexes; the sexes did not differ significantly. Males displayed higher AD/HD symptom rates overall. There was a significant correlation between body FA and the WURS measure in females after Bonferroni correction (P = 0.002, r(2) = 0.058). Thus, AD/HD symptoms levels increased with an increase in body FA in female college students not selected for AD/HD.

Attention-deficit hyperactivity disorder (AD/HD) and fluctuating asymmetry (FA) in a college sample: an exploratory study

Departures from normal development can be partly assessed by measuring fluctuating asymmetry (FA), that is, differences from perfect symmetry in traits that display bilateral symmetry. Attention-deficit hyperactivity disorder (AD/HD), one of the most common psychiatric conditions, is diagnosed if there are developmentally inappropriate levels of inattention, hyperactivity, and impulsivity. The objective here is to measure whether AD/HD behaviors positively correlate with FA in head, hands, and fingerprints of a sample of college students (n = 176, 57 male, 119 female) not selected for AD/HD. FA was measured as the absolute value of the difference between right and left sides divided by group mean trait size. Average FAs (mean, SE) were lowest for finger lengths (e.g., male, 3rd, 0.011 +/- 0.001; female, 3rd, 0.012 +/- 0.001) and highest for digit ridge counts (e.g., male, 5th, 0.075 +/- 0.007; female, 2nd, 0.069 +/- 0.005). Average FAs were similar between the sexes and only one facial measure and the facial index (summed FAs) differed significantly between the sexes (F > M). The scores for measures of the adult AD/HD behavioral assessment instrument, the Wender Utah Rating Scale (WURS) were high overall in this sample and males exhibited higher rates of symptoms than females. A Rasch measurement model analysis of individual responses to the WURS produced a true interval score for each person that is a measure of individual "AD/HDness." FA indices were then regressed on Rasch scores. A univariate analysis of all the variables demonstrated a significant interaction of sex. Hand, Dermatoglyphic, Face, and Total Indices were then regressed by sex on the Rasch values of "AD/HDness." Only in males was there a trend for the Dermatoglyphic Index (F(1,55) = 3.627, P = 0.062) and Total Index (F(1,55) = 3.811, P = 0.056) to increase as AD/HDness increases.