Sensitive intelligence
Gary McKeown
Review of General Psychology, forthcoming
Abstract:
This integrative review presents a novel hypothesis as a basis for integrating two evolutionary viewpoints on the origins of human cognition and communication, the sexual selection of human mental capacities, and the social brain hypothesis. This new account suggests that mind-reading social skills increased reproductive success and consequently became targets for sexual selection. The hypothesis proposes that human communication has three purposes: displaying mind-reading abilities, aligning and maintaining representational parity between individuals to enable displays, and the exchange of propositional information. Intelligence, creativity, language, and humor are mental fitness indicators that signal an individual’s quality to potential mates, rivals, and allies. Five features central to the proposed display mechanism unify these indicators, the relational combination of concepts, large conceptual knowledge networks, processing speed, contextualization, and receiver knowledge. Sufficient between-mind alignment of conceptual networks allows displays based upon within-mind conceptual mappings. Creative displays communicate previously unnoticed relational connections and novel conceptual combinations demonstrating an ability to read a receiver’s mind. Displays are costly signals of mate quality with costs incurred in the developmental production of the neural apparatus required to engage in complex displays and opportunity costs incurred through time spent acquiring cultural knowledge. Displays that are fast, novel, spontaneous, contextual, topical, and relevant are hard-to-fake for lower quality individuals. Successful displays result in elevated social status and increased mating options. The review addresses literatures on costly signaling, sexual selection, mental fitness indicators, and the social brain hypothesis; drawing implications for nonverbal and verbal communication.
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When the Mind Races: Effects of Thought Speed on Feeling and Action
Emily Pronin
Current Directions in Psychological Science, August 2013, Pages 283-288
Abstract:
Thought speed can be altered via controlled exposure to stimuli such as temporally paced text. Experiments show that thinking quickly induces positive mood and that the effect cannot be attributed to alterations of thought content or fluency. The effect is obtained across varied manipulations, including ones that alter the pace of thought involved in reading, problem solving, and visual comprehension. The experience of thinking fast signals a basic imperative for action and triggers a set of responses that mobilize the individual to act. These responses include not only heightened positive affect but also changes in behavior (i.e., increased risk taking), self-perception (i.e., increased self-confidence), and problem solving (i.e., increased creative insight). Implications of these thought-speed effects are discussed with respect to both everyday experiences that induce fast thinking and clinical psychiatric conditions (e.g., depression and mania) that are characterized by thought-speed abnormalities.
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Nature, nurture, and expertise
Robert Plomin et al.
Intelligence, forthcoming
Abstract:
Rather than investigating the extent to which training can improve performance under experimental conditions (‘what could be’), we ask about the origins of expertise as it exists in the world (‘what is’). We used the twin method to investigate the genetic and environmental origins of exceptional performance in reading, a skill that is a major focus of educational training in the early school years. Selecting reading experts as the top 5% from a sample of 10,000 12-year-old twins assessed on a battery of reading tests, three findings stand out. First, we found that genetic factors account for more than half of the difference in performance between expert and normal readers. Second, our results suggest that reading expertise is the quantitative extreme of the same genetic and environmental factors that affect reading performance for normal readers. Third, growing up in the same family and attending the same schools account for less than a fifth of the difference between expert and normal readers. We discuss implications and interpretations (‘what is inherited is DNA sequence variation’; ‘the abnormal is normal’). Finally, although there is no necessary relationship between ‘what is’ and ‘what could be’, the most far-reaching issues about the acquisition of expertise lie at the interface between them (‘the nature of nurture: from a passive model of imposed environments to an active model of shaped experience’).
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The Kid's Speech: The Effect of Stuttering on Human Capital Acquisition
Daniel Rees & Joseph Sabia
Economics of Education Review, forthcoming
Abstract:
A number of studies have shown that childhood speech impairments such as stuttering are associated with lower test scores and educational attainment. However, it is unclear whether this result is causal in nature or whether it can be explained by difficult-to-measure heterogeneity at the community, family, or individual level. Using data from the National Longitudinal Study of Adolescent Health and ordinary least squares, we show that stuttering is negatively associated with high school grades, the probability of high school graduation, and the probability of college attendance. However, empirical specifications with family fixed effects or controls for learning disabilities such as Attention Deficit Hyperactivity Disorder suggest that these associations can, in large part, be explained by difficult-to-measure heterogeneity.
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Learning-induced neural plasticity of speech processing before birth
Eino Partanen et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Learning, the foundation of adaptive and intelligent behavior, is based on plastic changes in neural assemblies, reflected by the modulation of electric brain responses. In infancy, auditory learning implicates the formation and strengthening of neural long-term memory traces, improving discrimination skills, in particular those forming the prerequisites for speech perception and understanding. Although previous behavioral observations show that newborns react differentially to unfamiliar sounds vs. familiar sound material that they were exposed to as fetuses, the neural basis of fetal learning has not thus far been investigated. Here we demonstrate direct neural correlates of human fetal learning of speech-like auditory stimuli. We presented variants of words to fetuses; unlike infants with no exposure to these stimuli, the exposed fetuses showed enhanced brain activity (mismatch responses) in response to pitch changes for the trained variants after birth. Furthermore, a significant correlation existed between the amount of prenatal exposure and brain activity, with greater activity being associated with a higher amount of prenatal speech exposure. Moreover, the learning effect was generalized to other types of similar speech sounds not included in the training material. Consequently, our results indicate neural commitment specifically tuned to the speech features heard before birth and their memory representations.
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Matthew Fugate, Sydney Zentall & Marcia Gentry
Gifted Child Quarterly, October 2013, Pages 234-246
Abstract:
There have been some behavioral indicators and some types of task performance that suggest greater creativity in students with attention deficit hyperactive disorder (ADHD). This evidence would appear counterintuitive given that lower working memory (i.e., holding information in mind for novel recombinations) has often been documented in students with ADHD. Thus, the purpose of this study was to assess working memory and creativity in two groups of gifted students (i.e., with characteristics of ADHD, n = 17, and without ADHD characteristics, n = 20), who were equivalent in fluid intelligence. Significant differences were found indicating that gifted students with ADHD characteristics had not only poorer working memory but also significantly greater creativity than those gifted students without these characteristics. These results were discussed in terms of creative potential, which could serve as an identifier and as a pathway to instruction.
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Ability rise in NAEP and narrowing ethnic gaps?
Heiner Rindermann & James Thompson
Intelligence, forthcoming
Abstract:
US National Assessment of Educational Progress (NAEP) results from 1971 to 2008 enable four different effects to be distinguished: Cohort rise effects, gap-narrowing between ethnic groups, trends due to demographic changes in by NAEP listed or not listed ethnic groups. NAEP means and percentiles in reading and mathematics were transformed to conventional IQs and SDs. The total increase from 1971 to 2008 was in the scale of 4.34 IQ points (dec = 1.17 IQ per decade). The ability distribution became more homogenous (down from SD = 15.00 in 1971 to SD = 13.56 in 2008). Increases were larger for younger students (9-year olds: 2.02 IQ per decade; 13-year olds: 1.20; 17-year olds: 0.30); larger at the lower ability level (10th percentile dec = 1.79 vs. 90th percentile dec = 1.03). The largest increase was for Blacks (Whites dec = 1.29 IQ, Hispanics 2.27, Blacks 3.04). White–Hispanic-differences were reduced from 11.59 to 8.46 IQ, White–Black from 16.33 to 9.94 IQ. If the racial composition of the population had not changed, the mean gain for the 17-year-old group would have been 2.47 IQ points higher. Had the gap between Whites and the two other groups not narrowed, the mean gain would have been 1.70 IQ points lower. Demographic change has accounted for a loss of 2.47 IQ points and according to cognitive human capital theory $2001 GDP per capita per year, but total ethnic gap-narrowing has provided a gain of $1377.
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Oxytonergic circuitry sustains and enables creative cognition in humans
Carsten De Dreu et al.
Social Cognitive and Affective Neuroscience, forthcoming
Abstract:
Creativity enables humans to adapt flexibly to changing circumstances, to manage complex social relations and to survive and prosper through social, technological and medical innovations. In humans, chronic, trait-based as well as temporary, state-based approach orientation has been linked to increased capacity for divergent rather than convergent thinking, to more global and holistic processing styles and to more original ideation and creative problem solving. Here, we link creative cognition to oxytocin, a hypothalamic neuropeptide known to up-regulate approach orientation in both animals and humans. Study 1 (N = 492) showed that plasma oxytocin predicts novelty-seeking temperament. Study 2 (N = 110) revealed that genotype differences in a polymorphism in the oxytocin receptor gene rs1042778 predicted creative ideation, with GG/GT-carriers being more original than TT-carriers. Using double-blind placebo-controlled between-subjects designs, Studies 3–6 (N = 191) finally showed that intranasal oxytocin (vs matching placebo) reduced analytical reasoning, and increased holistic processing, divergent thinking and creative performance. We conclude that the oxytonergic circuitry sustains and enables the day-to-day creativity humans need for survival and prosperity and discuss implications.
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Early Handedness in Infancy Predicts Language Ability in Toddlers
Eliza Nelson, Julie Campbell & George Michel
Developmental Psychology, forthcoming
Abstract:
Researchers have long been interested in the relationship between handedness and language in development. However, traditional handedness studies using single age groups, small samples, or too few measurement time points have not capitalized on individual variability and may have masked 2 recently identified patterns in infants: those with a consistent hand-use preference and those with an inconsistent preference. In this study, we asked whether a consistent infant hand-use preference is related to later language ability. We assessed handedness in 38 children at monthly intervals from 6–14 months (infant visits) and again from 18–24 months (toddler visits). We found that consistent right-handedness during infancy was associated with advanced language skills at 24 months, as measured by the Bayley Scales of Infant and Toddler Development (Bayley–III; Bayley, 2006). Children who were not lateralized as infants but who became right-handed or left-handed as toddlers had typical language scores. Neither timing nor direction of lateralization was related to cognitive or general motor skills. This study builds on previous literature linking right-handedness and language during the first 2 years of life.
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Marc Bornstein, Chun-Shin Hahn & Joan Suwalsky
Psychological Science, forthcoming
Abstract:
A developmental cascade defines a longitudinal relation in which one psychological characteristic uniquely affects another psychological characteristic later in time, separately from other intrapersonal and extrapersonal factors. Here, we report results of a large-scale (N = 374), normative, prospective, 14-year longitudinal, multivariate, multisource, controlled study of a developmental cascade from infant motor-exploratory competence at 5 months to adolescent academic achievement at 14 years, through conceptually related and age-appropriate measures of psychometric intelligence at 4 and 10 years and academic achievement at 10 years. This developmental cascade applied equally to girls and boys and was independent of children’s behavioral adjustment and social competence; mothers’ supportive caregiving, verbal intelligence, education, and parenting knowledge; and the material home environment. Infants who were more motorically mature and who explored more actively at 5 months of age achieved higher academic levels as 14-year-olds.
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Acute Effects of Modafinil on Brain Resting State Networks in Young Healthy Subjects
Roberto Esposito et al.
PLoS ONE, July 2013
Background: There is growing debate on the use of drugs that promote cognitive enhancement. Amphetamine-like drugs have been employed as cognitive enhancers, but they show important side effects and induce addiction. In this study, we investigated the use of modafinil which appears to have less side effects compared to other amphetamine-like drugs. We analyzed effects on cognitive performances and brain resting state network activity of 26 healthy young subjects.
Methodology: A single dose (100 mg) of modafinil was administered in a double-blind and placebo-controlled study. Both groups were tested for neuropsychological performances with the Raven’s Advanced Progressive Matrices II set (APM) before and three hours after administration of drug or placebo. Resting state functional magnetic resonance (rs-FMRI) was also used, before and after three hours, to investigate changes in the activity of resting state brain networks. Diffusion Tensor Imaging (DTI) was employed to evaluate differences in structural connectivity between the two groups.
Principal Findings: Results indicate that a single dose of modafinil improves cognitive performance as assessed by APM. Rs-fMRI showed that the drug produces a statistically significant increased activation of Frontal Parietal Control (FPC; p<0.04) and Dorsal Attention (DAN; p<0.04) networks. No modifications in structural connectivity were observed.
Conclusions and Significance: Overall, our findings support the notion that modafinil has cognitive enhancing properties and provide functional connectivity data to support these effects.
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Long-term effects of LCPUFA supplementation on childhood cognitive outcomes
John Colombo et al.
American Journal of Clinical Nutrition, August 2013, Pages 403-412
Background: The effect of long-chain polyunsaturated fatty acid (LCPUFA) intake on cognitive development is controversial. Most randomized trials have assessed cognition at 18 mo, although significant development of cognitive abilities (early executive function) emerge later.
Objective: The objective was to evaluate cognition beyond 18 mo and longitudinal cognitive change from 18 mo to 6 y in children who were fed variable amounts of docosahexaenoic acid (0.32%, 0.64%, and 0.96% of total fatty acids) and arachidonic acid (ARA; 0.64%) compared with children who were not fed LCPUFA as infants.
Design: Eighty-one children (19 placebo, 62 LCPUFA) who participated in a double-blind, randomized trial of LCPUFA supplementation as infants were re-enrolled at 18 mo and tested every 6 mo until 6 y on age-appropriate standardized and specific cognitive tests.
Results: LCPUFA supplementation did not influence performance on standardized tests of language and performance at 18 mo; however, significant positive effects were observed from 3 to 5 y on rule-learning and inhibition tasks, the Peabody Picture Vocabulary Test at 5 y, and the Weschler Primary Preschool Scales of Intelligence at 6 y. Effects of LCPUFAs were not found on tasks of spatial memory, simple inhibition, or advanced problem solving.
Conclusions: The data from this relatively small trial suggest that, although the effects of LCPUFAs may not always be evident on standardized developmental tasks at 18 mo, significant effects may emerge later on more specific or fine-grained tasks. The results imply that studies of nutrition and cognitive development should be powered to continue through early childhood.
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Intergenerational Continuity in School Performance: Do Grandparents Matter?
Bitte Modin, Robert Erikson & Denny Vågerö
European Sociological Review, August 2013, Pages 858-870
Abstract:
We investigate whether present-day ninth grade students with top marks in Swedish and mathematics tend to descend from grandparents who did well in these school-subjects too. We also examine the extent to which such inheritance is domain-specific and works through the educational attainment of the previous two generations. The study is based on grandsons (n = 6,110) and granddaughters (n = 5,658) of subjects born in Uppsala 1915–1929. Results show that the odds of students receiving top marks in mathematics and Swedish tend to increase the higher the marks their grandparents achieved in these subjects. However, associations differ by the specific school-subject and according to the gender-specific intergenerational line of transmission. In broad terms, our results indicate that grandfathers are important for the transmission of mathematical and linguistic ability to their granddaughters and grandsons. Grandmothers appear to play a smaller role in the transmission of abilities, with the distinct exception of the transmission of linguistic ability from maternal grandmothers to their granddaughters. The fact that associations vary quite strongly according to type of ability and the gender-specific line of intergenerational transmission implies that we should be looking to historical context and learning environments rather than to a simple genetic transmission model to explain our findings.
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Socioeconomic status and functional brain development – associations in early infancy
Przemyslaw Tomalski et al.
Developmental Science, September 2013, Pages 676–687
Abstract:
Socioeconomic status (SES) impacts on both structural and functional brain development in childhood, but how early its effects can be demonstrated is unknown. In this study we measured resting baseline EEG activity in the gamma frequency range in awake 6–9-month-olds from areas of East London with high socioeconomic deprivation. Between-subject comparisons of infants from low- and high-income families revealed significantly lower frontal gamma power in infants from low-income homes. Similar power differences were found when comparing infants according to maternal occupation, with lower occupational status groups yielding lower power. Infant sleep, maternal education, length of gestation, and birth weight, as well as smoke exposure and bilingualism, did not explain these differences. Our results show that the effects of socioeconomic disparities on brain activity can already be detected in early infancy, potentially pointing to very early risk for language and attention difficulties. This is the first study to reveal region-selective differences in functional brain development associated with early infancy in low-income families.
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Rajeev Krishnadas et al.
Psychosomatic Medicine, forthcoming
Objective: Neighborhood-level socioeconomic deprivation has been associated with poor cognitive function pertaining to language and the executive control. Few studies have explored the cortical morphology of regions most commonly associated with these functions. The aim of this study was to examine the association between neighborhood-level deprivation and the morphology of cortical regions associated with language and executive control in adults.
Methods: Using a cross-sectional study design, we compared the cortical morphology of 42 neurologically healthy adult men from the least deprived and most deprived neighborhoods of Glasgow. We performed surface-based morphometry on 3-T structural magnetic resonance imaging (MRI) images to extract the cortical morphology — volume, thickness (CT), and surface area (SA) of regions commonly associated with language and executive control. Cortical morphology was compared between the two groups. We used mediation analysis to examine whether cardiometabolic risk factors mediated the relationship between deprivation status and cortical morphology.
Results: Intracranial volume and mean total CT did not differ between groups. The deprived group had significantly smaller left posterior parietal cortex SA (Cohen d = 0.89) and fusiform cortex SA (Cohen d = 1.05). They also had thinner left Wernicke’s area (Cohen d =0.93) and its right homologue (Cohen d = 1.12). Among the cardiometabolic markers, a composite factor comprising inflammatory markers mediated the relationship between deprivation status and Wernicke’s area CT.
Conclusions: A group of neurologically healthy men from deprived neighborhoods showed significantly smaller cortical morphology — both SA and CT — in regions of the brain pertaining to language and executive function. We provide additional evidence of a relationship between socioeconomic deprivation and cortical morphology.
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Count on dopamine: Influences of COMT polymorphisms on numerical cognition
Annelise Júlio-Costa et al.
Frontiers in Psychology, August 2013
Abstract:
Catechol-O-methyltransferase (COMT) is an enzyme that is particularly important for the metabolism of dopamine. Functional polymorphisms of COMT have been implicated in working memory and numerical cognition. This is an exploratory study that aims at investigating associations between COMT polymorphisms, working memory, and numerical cognition. Elementary school children from 2th to 6th grades were divided into two groups according to their COMT val158met polymorphism [homozygous for valine allele (n = 61) vs. heterozygous plus methionine homozygous children or met+ group (n = 94)]. Both groups were matched for age and intelligence. Working memory was assessed through digit span and Corsi blocks. Symbolic numerical processing was assessed through transcoding and single-digit word problem tasks. Non-symbolic magnitude comparison and estimation tasks were used to assess number sense. Between-group differences were found in symbolic and non-symbolic numerical tasks, but not in working memory tasks. Children in the met+ group showed better performance in all numerical tasks while val homozygous children presented slower development of non-symbolic magnitude representations. These results suggest COMT-related dopaminergic modulation may be related not only to working memory, as found in previous studies, but also to the development of magnitude processing and magnitude representations.