Zach Hambrick

• Michigan State University

Limited empirical evidence exists to describe and classify the effects of professional inactivity on the competence of physical therapists (PTs) and physical therapist assistants (PTAs) who may return to practice after extended absences from patient care. This article presents results of the first empirical study concerning the nature of PT and PTA...

The deliberate practice (DP) theory claims that expertise essentially reflects the accumulated amount of deliberate practice, and that with sufficient practice, genetic influences on expertise will be bypassed. Thus, a core prediction of the DP theory is that genetic effects on performance decrease as a function of practice. Here, we test this pred...

Background The video-based temporal occlusion paradigm has been consistently used in visual anticipation sport research. Objective This meta-analysis investigated the magnitude to which video-based temporal occlusion training could improve anticipation skill with transfer to representative laboratory and field tasks. Methods As there are consider...

Scores on the Armed Services Vocational Aptitude Battery (ASVAB) predict military job (and training) performance better than any single variable so far identified. However, it remains unclear what factors explain this predictive relationship. Here, we investigated the contributions of fluid intelligence (Gf) and two executive functions—placekeeping...

Decades of research in industrial–organizational psychology have established that measures of general cognitive ability (g) consistently and positively predict job-specific performance to a statistically and practically significant degree across jobs. But is the validity of g stable across different levels of job experience? The present study addre...

Background To what extent does junior athletic performance predict senior athletic performance (i.e., in the highest, open-age category)? This question is the subject of a lively debate in the literature. Following traditional theories of giftedness and expertise, some researchers and practitioners have proposed that a high level of junior performa...

There has been a longstanding debate about the question: What amounts of what types of youth sport activities optimally facilitate later athletic excellence? This article provides a review of relevant research. We first evaluate popular conceptualizations of participation patterns—early specialization, deliberate practice, and deliberate play. Then...

We asked whether people performing different versions of a procedural task would adapt to the differences and achieve similarly high levels of performance. In Experiment 1 (N = 479), participants either did or did not receive a mnemonic for the sequence of procedural steps. Both groups had unlimited access to a help function giving the sequence. No...

Background To what extent does the pathway to senior elite success build on junior elite success? Evidence from longitudinal studies investigating athletes’ junior-to-senior performance development is mixed; prospective studies have reported percentages of juniors who achieved an equivalent competition level at senior age (e.g., international champ...

Most research on skilled performance is correlational, with skill and predictors measured at a single point in time, making it difficult to draw conclusions about the acquisition of skill. By contrast, in this study, we trained novice participants (N = 79) to solve Rubik’s Cubes using a 7-step solution method. Participants also completed measures o...

Scores on the ACT college entrance exam predict college grades to a statistically and practically significant degree, but what explains this predictive validity? The most obvious possibility is general intelligence—or psychometric “g”. However, inconsistent with this hypothesis, even when independent measures of g are statistically controlled, ACT...

Many cognitive tasks have what we refer to as a placekeeping requirement: steps or subtasks must be performed in a linear or other systematic fashion, without repetitions or omissions that would compromise performance. Here we asked whether the cognitive control mechanisms that meet this requirement are specific to individual tasks or general enoug...

Scores on standardized tests of intelligence meaningfully predict certain real-world outcomes, including those reflecting performance in complex real-world tasks. At the same time, research on intelligence has been conducted in a largely acontextual fashion, overlooking the importance both of other individual-difference factors and environmental fa...

Expert sport performers cope with a multitude of visual information to achieve precise skill goals under time stress and pressure. For example, a major league baseball or cricket batter must read opponent variations in actions and ball flight paths to strike the ball in less than a second. Crowded playing schedules and training load restrictions to...

The self-generation effect refers to the finding that people’s memory for information tends to be better when they generate it themselves. Counterintuitively, when proofreading, this effect may make it more difficult to detect mistakes in one’s own writing than in others’ writing. We investigated the self-generation effect and sources of individual...

Background Does early specialization facilitate later athletic excellence, or is early diversification better? This is a longstanding theoretical controversy in sports science and medicine. Evidence from studies investigating athletes’ starting age, childhood/adolescent progress, and amounts of coach-led practice and peer-led play in their main spo...

Musical expertise exists along a continuum, with some musicians demonstrating far greater mastery than others. What accounts for this variability in skill? Could anyone, given the right conditions, reach a level of skill necessary to play for a first-rank orchestra? As a more extreme example, could anyone compose a symphonic masterpiece or play the...

A hallmark of intelligent behavior is rationality – the disposition and ability to think analytically to make decisions that maximize expected utility or follow the laws of probability. However, the question remains as to whether rationality and intelligence are empirically distinct, as does the question of what cognitive mechanisms underlie indivi...

What explains the acquisition of exceptional human performance? Does a focus on intensive specialized practice facilitate excellence, or is a multidisciplinary practice background better? We investigated this question in sports. Our meta-analysis involved 51 international study reports with 477 effect sizes from 6,096 athletes, including 772 of the...

Multitasking is ubiquitous in everyday life, which means there is value in developing measures that predict successful multitasking performance. In a large sample (N = 404 contributing data), we examined the predictive and incremental validity of placekeeping, which is the ability to perform a sequence of operations in a certain order without omiss...

In a recent Psychological Research article, Moxley, Ericsson, and Tuffiash (2017) report two studies of SCRABBLE expertise. The results revealed that the average SCRABBLE rating was higher for males than for females. Moreover, correlational and structural equation analyses revealed that activities that the authors refer to as “purposeful practice”...

A hallmark of intelligent behavior is rationality—the disposition and ability to think analytically to make decisions that maximize expected utility or follow the laws of probability, and therefore align with normative principles of decision making. However, the question remains as to whether rationality and intelligence are empirically distinct, a...

The question of what individual differences in working memory capacity reflect has been a topic of intensive interest in research for several decades. This research has shed light on mechanisms underlying working memory performance. At the same time, the chapter authors argue this research has been myopic in two respects. First, it has largely igno...

Working memory refers to how we keep track of what we are doing moment to moment throughout our waking lives. It allows us to remember what we have just done, focus on what we are doing now, to solve problems, be creative, think about what we will be doing in the next few seconds, and continually to update in our mind changes around us throughout t...

Mindset interventions are designed to encourage students to adopt a growth mindset, reflecting the belief that one's intelligence can be improved in an effort to increase academic achievement. How do these interventions exert their effects? We assessed the effects of an online mindset intervention on mindset and four outcome variables, grit, locus...

The question of what explains individual differences in expertise within complex domains such as music, games, sports, science, and medicine is currently a major topic of interest in a diverse range of fields, including psychology, education, and sports science, to name just a few. Ericsson and colleagues’ deliberate practice view is a highly influ...

Mind-set refers to people’s beliefs about whether attributes are malleable ( growth mind-set) or unchangeable ( fixed mind-set). Proponents of mind-set theory have made bold claims about mind-set’s importance. For example, one’s mind-set is described as having profound effects on one’s motivation and achievements, creating different psychological w...

In this chapter we discuss the link between intelligence and problem-solving. To preview, we argue that the ability to solve problems is not just an aspect or feature of intelligence – it is the essence of intelligence. We briefly review evidence from psychometric research concerning the nature of individual differences in intelligence, and then re...

Studies of expertise have traditionally had a strong focus on the role of one single factor, i.e. long-term deliberate practice, for expert performance. However, recent empirical and theoretical work strongly suggests that expertise is a function of many variables that may have practice-independent effects on performance, but also moderate the effi...

Although binocular rivalry is different from other perceptually bistable phenomena in requiring interocular conflict, it also shares numerous features with those phenomena. This raises the question of whether, and to what extent, the neural bases of binocular rivalry and other bistable phenomena overlap. Here we examine this question using an indiv...

People with high levels of expertise in domains such as science, business, law, and music contribute to the prosperity of nations, the competitive advantage of organizations, and the well-being of families and communities. These individuals are often revered by society for their contributions—think of Marie Curie in science, The Beatles in popular...

The field of expertise is mired in a nature vs. nurture debate. Despite what we now know from behavioral genetics research about the underpinnings of human behavior, some expertise theorists continue to deny or downplay the importance of genetic factors ("innate talent") in expert performance. In this commentary, we argue that this viewpoint is nei...

It is well established that measures of reasoning ability and of working memory capacity (WMC) correlate positively. However, the question of what explains this relationship remains open. The purpose of this study was to investigate the capacity hypothesis, which ascribes causality to WMC. This hypothesis holds that people high in WMC are more succ...

How important are training and other forms of domain-relevant experience in predicting individual differences in expertise? To answer this question, we used structural equation modeling to reanalyze data from a study of chess by Charness, Tuffiash, Krampe, Reingold, and Vasyukova (2005). Latent variables reflecting serious chess activity and formal...

This chapter reviews evidence concerning the contribution of cognitive ability to individual differences in expertise. The review covers research in traditional domains for expertise research such as music, sports, and chess, as well as research from industrial–organizational psychology on job performance. The specific question that we seek to addr...

Several currently popular areas of research—brain training, mind-set, grit, deliberate practice, and the bilingual advantage—are premised on the idea that environmental factors are the overwhelming determinants of success in real-world pursuits. Here, we describe the major claims from each of these areas of research and discuss evidence for these c...

We adjusted for dependent performance measures using a method based on Cheung and Chan, 2004, Cheung and Chan, 2008 method. Cheung and Chan's method adjusts the sample size to be between the sample N and the cumulative sample N, and applies this to the average of the dependent effect sizes. Their adjustment formula is as follows: adjusted N = ((N−1...

When a person explores a new environment, they begin to construct a spatial representation of it. Doing so is important for navigating and remaining oriented. How does one’s ability to learn a new environment relate to one’s ability to remember experiences in that environment? Here, 208 adults experienced a first-person videotaped route, and then c...

Mindset refers to a person’s beliefs about the nature of their abilities—whether they believe their ability in a given domain is malleable or fixed. We investigated whether a brief, online intervention could alter ability and non-ability traits, including mindset of intelligence, locus of control, challenge-approach motivation, grit, and performanc...

When a person explores a new environment, they begin to construct a spatial representation of it. Doing so is important for navigating and remaining oriented. How does one’s ability to learn a new environment relate to one’s ability to remember experiences in that environment? Here, 208 adults experienced a first-person videotaped route, and then c...

Multiple frameworks for categorizing spatial abilities exist but it has been difficult to verify them using exploratory factor analysis. The present study tested one of these frameworks-a 2 × 2 classification scheme that crossed the dimensions of static/dynamic and intrinsic/extrinsic (Uttal et al., 2013)-using confirmatory factor analysis with dat...

The circumvention-of-limits hypothesis holds that the more expert (i.e., knowledgeable) the task performer, the less it matters for task performance whether that person has limited general cognitive ability. We tested this hypothesis using a knowledge-activation approach to manipulate knowledge experimentally. The criterion task, which we designed...

The debate over the origins of individual differences in expertise has raged on for over a century in psychology. The “nature” view holds that expertise reflects “innate talent”—that is, genetically-determined abilities. The “nurture” view counters that if talent even exists, its effects on ultimate performance are negligible. While no scientist ta...

Scientists identify 22 genes associated with intelligence. Full Text: https://www.scientificamerican.com/article/intelligence-and-the-dna-revolution/

In a previous study, Mix, Levine, Cheng, Young, et al. (2016) reported that spatial skill and mathematics were comprised of two highly correlated, domain-specific factors, with a few cross-domain loadings. The overall structure was consistent across grade (K, 3, 6) but the cross-loadings varied with age. The present study sought to replicate these...

Positive effects of practice are ubiquitous in human performance, but a finding from memory research suggests that negative effects are possible also. The finding is that memory for items on a list depends on the time interval between item presentations. This finding predicts a negative effect of practice on procedural performance under conditions...

Green et al. (2017) raise two broad concerns with our two studies (Unsworth et al., 2015) showing little association between self-reported video-game experience and cognitive abilities: (a) Our analyses assumed linear gaming-cognition relationships and ignored possible confounding associations among different video-game genres, and (b) the video-ga...

We investigated effects of task interruption on procedural performance, focusing on the effect of interruption length on the rates of different categories of error at the point of task resumption. Interruption length affected errors involving loss of place in the procedure (sequence errors) but not errors involving incorrect execution of a correct...

Substantial research in the psychology of expertise has shown that experts in several fields (e.g., science, mathematics) perform better than non-experts on standardized tests of intelligence. This evidence suggests that intelligence plays an important role in the acquisition of expertise. However, a counter argument is that the difference between...

http://www.scientificamerican.com/article/is-innate-talent-a-myth/

Ericsson and colleagues’ view that individual differences in expertise can largely be accounted for by accumulated deliberate practice is not supported by the available empirical evidence. Extending earlier work (Macnamara, Hambrick, & Oswald, 2014), we found that deliberate practice accounted for a sizeable amount of variance in sports performance...

Why are some people so much more successful than other people in music, sports, games, business, and other complex domains? This question is the subject of one of psychology's oldest debates. Over 20 years ago, Ericsson, Krampe, and Tesch-Römer (1993) proposed that individual differences in performance in domains such as these largely reflect accum...

Questions about how expertise is acquired, and how it changes with age in adulthood, have long been of interest to psychologists. Beginning in the late 1960s, research established that novices and experts differ in acquired skills, such as the ability to perceive meaningful patterns of information. The view that emerged from this research was that...

Psychometric intelligence (g) is often conceptualized as the capability for online information processing but it is also possible that intelligence may be related to offline processing of information. Here, we investigated the relationship between psychometric g and sleep-dependent memory consolidation. Participants studied paired-associates and we...

The relations between video-game experience and cognitive abilities were examined in the current study. In two experiments, subjects performed a number of working memory, fluid intelligence, and attention-control measures and filled out a questionnaire about their video-game experience. In Experiment 1, an extreme-groups analysis indicated that exp...

This Research Topic sought to advance psychological understanding of expertise by drawing together lines of research from many different domains of expertise. The outcome is a collection of 35 articles in such diverse areas as chess, music, perception, teaching, intensive-care diagnosis, video-games, sports, dance, mathematics, climbing, and finger...

The question of what underlies individual differences in general intelligence has never been satisfactorily answered. The purpose of this research was to investigate the role of an executive function that we term placekeeping ability—the ability to perform the steps of a complex task in a prescribed order without skipping or repeating steps. Partic...

Working memory capacity is one of the most frequently measured individual difference constructs in cognitive psychology and related fields. However, implementation of complex span and other working memory measures is generally time-consuming for administrators and examinees alike. Because researchers often must manage the tension between limited te...

The use of laptops and cell phones in the classroom is increasing but there is little research assessing whether these devices create distraction that diminishes learning. Moreover, the contribution of intellectual ability to the relationship between learning and portable device use has not been thoroughly investigated. To bridge this gap, students...

More than 20 years ago, researchers proposed that individual differences in performance in such domains as music, sports, and games largely reflect individual differences in amount of deliberate practice, which was defined as engagement in structured activities created specifically to improve performance in a domain. This view is a frequent topic o...

Working memory is a critical element of complex cognition, particularly under conditions of distraction and interference. Measures of working memory capacity correlate positively with many measures of real-world cognition, including fluid intelligence. There have been numerous attempts to use training procedures to increase working memory capacity...

Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segmen...

Geologic mapping draws heavily on 3D visualization, as the geologist must navigate through unfamiliar terrain, observing and interpreting scattered surface rock outcrops to create an accurate mental representation of the 3D subsurface geology. The geologist must then transfer a 3D mental representation onto a 2D geologic map. Geological knowledge i...

Twenty years ago, Ericsson, Krampe, and Tesch-Römer (1993) proposed that expert performance reflects a long period of deliberate practice rather than innate ability, or “talent”. Ericsson et al. found that elite musicians had accumulated thousands of hours more deliberate practice than less accomplished musicians, and concluded that their theoretic...

Deficits in memory for everyday activities are common complaints among healthy and demented older adults. The medial temporal lobes and dorsolateral prefrontal cortex are both affected by aging and early-stage Alzheimer's disease, and are known to influence performance on laboratory memory tasks. We investigated whether the volume of these structur...

We investigated the effect of short interruptions on performance of a task that required participants to maintain their place in a sequence of steps each with their own performance requirements. Interruptions averaging 4.4 s long tripled the rate of sequence errors on post-interruption trials relative to baseline trials. Interruptions averaging 2.8...

When memory is tested after a delay, performance is typically better if the retention interval includes sleep. However, it is unclear what accounts for this well-established effect. It is possible that sleep enhances the retrieval of information, but it is also possible that sleep protects against memory loss that normally occurs during waking acti...

Numerous recent studies seem to provide evidence for the general intellectual benefits of working memory training. In reviews of the training literature, Shipstead, Redick, and Engle (2010, 2012) argued that the field should treat recent results with a critical eye. Many published working memory training studies suffer from design limitations (no-c...

Bedrock geologic mapping is a complex and cognitively demanding task. Successful mapping requires domain-specific content knowledge, visuospatial ability, navigation through the field area, creating a mental model of the geology that is consistent with field data, and metacognition. Most post-secondary geology students in the United States receive...

Domain knowledge is a powerful predictor of success in many complex tasks, but do general cognitive abilities also play a role? To investigate this question, we had 155 participants representing a wide range of poker experience and skill complete tests of poker knowledge, working memory capacity (WMC), and two components of skill in Texas Hold’Em p...

Sources of individual differences in scientific problem solving were investigated. Participants representing a wide range of experience in geology completed tests of visuospatial ability and geological knowledge, and performed a geological bedrock mapping task, in which they attempted to infer the geological structure of an area in the Tobacco Root...

It is clear from decades of research that, to a very large degree, success in music, games, sports, science, and other complex domains reflects knowledge and skills acquired through experience. However, it is equally clear that basic abilities, which are known to be substantially heritable, also contribute to performance differences in many domains...

Siblings of children with autism spectrum disorders (ASD) may be at an increased risk of adjustment problems. To examine possible predictors of adjustment difficulties in siblings, 70 mothers with at least one child with ASD and one typical child completed surveys of symptom severity in the child with ASD, impact of the child with ASD on the siblin...

Decades of research have established that "online" cognitive processes, which operate during conscious encoding and retrieval of information, contribute substantially to individual differences in memory. Furthermore, it is widely accepted that "offline" processes during sleep also contribute to memory performance. However, the question of whether i...

This study investigated the relationship between ASVAB scores and multitasking performance in Navy Sailors. Sailors performed a "synthetic work" task designed to simulate demands for multitasking common to many different jobs, as well as elementary cognitive tasks designed to measure two mental processes-the ability to update the contents of workin...

This study examined the relationship between child symptom severity, parent broader autism phenotype (BAP), and stress and depression in parents of children with ASD. One hundred and forty-nine parents of children with ASD completed a survey of parenting stress, depression, broader autism phenotype, coping styles, perceived social support, and chil...

This study investigated determinants of success in a 'synthetic work' task designed to reflect the requirement for multitasking that is common to many occupations. Participants were administered tests of working memory capacity (WMC) and processing speed (PS), and they reported experience with videogames, a type of activity presumed to involve mult...

Deliberate practice-that is, engagement in activities specifically designed to improve performance in a domain-is strongly predictive of performance in domains such as music and sports. It has even been suggested that deliberate practice is sufficient to account for expert performance. Less clear is whether basic abilities, such as working memory c...

Attentional control has been conceptualized as executive functioning by neuropsychologists and as working memory capacity by experimental psychologists. We examined the relationship between these constructs using a factor analytic approach in an adult life span sample. Several tests of working memory capacity and executive function were administere...

The purpose of this study was to identify sources of individual differences in knowledge acquired under natural conditions. Through its direct influence on background knowledge, crystallized intelligence (Gc) had a major impact on political knowledge, acquired over a period of more than 2 months, but there were independent influences of personality...

The ability to ignore or control the processing of distracting information may underlie many age-related and individual differences in cognitive abilities. Using a large sample of adults aged 18 to 87 years, this article presents data examining the mediating role of distraction control in the relationship between age and higher order cognition. The...

The purpose of this study was to investigate sources of inter-individual differences in current events knowledge. The study occurred in two sessions. In the initial session, 579 participants completed tests to ability, personality, and interest factors, as well as prior knowledge of current events. Approximately 10 weeks later, participants complet...

In contextual cueing, the position of a search target is learned over repeated exposures to a visual display. The strength of this effect varies across stimulus types. For example, real-world scene contexts give rise to larger search benefits than contexts composed of letters or shapes. We investigated whether such differences in learning can be at...

The present study investigated the relative contributions of experiential and ability factors to second language (L2) passage comprehension and L2 vocabulary retention. Participants included a cross section of 99 adult learners of Spanish as a foreign language enrolled in beginning through advanced level university Spanish courses. Participants com...

Multitasking (MT) performance requires performing multiple tasks, appropriately shifting attention and prioritizing them. Successful multitaskers focus their attention on the task where attention is most needed at the moment, and they adapt to changes in task priority as they occur. It is this latter feature of multitasking that suggests a natural...

What accounts for individual differences in the sort of knowledge that people may draw on in everyday cognitive tasks, such as deciding whom to vote for in a presidential election, how to invest money in the stock market, or what team to bet on in a friendly wager? In a large sample of undergraduate students, we investigated correlates of individua...