Related Experiment Video
Updated: Dec 28, 2025
Block Building Task Identifies Distinct Groups of Left/Right-hand Choice Patterns After Unilateral Peripheral Nerve Injury
Published on: March 21, 2025
Measuring infant handedness reliably from reaching: A systematic review
Eliza L Nelson1, Sandy L Gonzalez1,2
1Department of Psychology, Florida International University, Miami, FL, USA.
Insights
Most studies measuring infant handedness using reaching tasks do not use enough trials for reliable results. A minimum of 15 trials is recommended for accurate infant handedness classification.
Area of Science:
- Developmental Psychology
- Neuroscience
Background:
- Infant handedness has been studied for over 100 years using reaching paradigms.
- Existing methodologies for assessing infant handedness lack standardization, leading to variability in results.
Purpose of the Study:
- To systematically review and synthesize studies on infant handedness assessment using reaching tasks.
- To evaluate the number of trials used in these studies against recommended criteria for reliable measurement.
- To establish a foundation for best practices in infant handedness research.
Main Methods:
- A systematic literature search was conducted using PRISMA guidelines across PsycINFO, PubMed, and Ovid MEDLINE.
- Studies published up to May 2018, focusing on infant reaching to index handedness, were included.
- 1,116 records were screened, with 87 articles undergoing qualitative synthesis based on trial number.
Main Results:
- The majority of published papers (70%) since 1890 fail to meet the recommended minimum of 15 trials for statistically reliable infant handedness measurement.
- Significant variation exists in the number of trials employed across studies.
- Few studies adhere to the recommended trial count for robust classification.
Conclusions:
- Current research practices for measuring infant handedness are often inadequate for reliable classification.
- Future research should prioritize adhering to a minimum trial count (e.g., 15 trials) to ensure methodological rigor.
- Establishing standardized protocols is crucial for advancing the field of infant handedness research.
Abstract:
Researchers have utilized reaching paradigms to measure infant handedness for more than a century. However, methods vary widely. Recent research has identified that the number of trials used in assessment is critical with the recommendation that at least 15 trials are necessary to reliably classify infants into handedness categories via statistical cutoffs. As a first step towards establishing best practices for the field, we identified, categorized, and synthesized findings according to trial number from studies that utilized reaching to index handedness in infants across the first two years of life using PRISMA guidelines. Database searches were conducted in PsycINFO, PubMed, and Ovid MEDLINE®. All articles published through May 2018 were included. Additional records were identified through other sources. After removing duplicates, 1,116 records were screened using the online software program Abstrackr. Of these records, 125 full-text articles were further assessed for eligibility, and 87 articles were included in the qualitative synthesis. Results revealed that the majority of papers published since 1890 (70%) do not meet the 15-trial minimum criterion for statistically reliable measurement of infant handedness. Broad themes from articles meeting the measurement criterion and implications for future research are discussed.
