Gaining the Upper Hand: Assessment and Handedness

Stephanie Miodus, M.A., M.Ed. & Frank Farley, Ph.D.


Understanding performance differences for left-handed learners on test batteries is critical for accurate assessments. This poster session will consider how left-handed learners perform on subtests that require written responses and the potential for adaptations to standard administration. Practitioners will be challenged to think about how left-handed learners perform depending on subtest design and how to interpret data from these subtests as it applies to left-handed learners in order to reduce the potential for test bias.


  • Handedness has been found to be important in many areas of human behavior and interest in the topic dates to early psychological research studies (Stromberg & Stromberg, 1938).

  • Yet, it is often currently overlooked in many aspects of psychological science, including the literature on educational (cognitive and academic) assessment.

  • Research is mixed on whether left-handed individuals show either higher, lower, or similar levels of intelligence and performance on different areas of academic achievement when compared to right-handed individuals (Ghayas & Adil, 2007; Lamm & Epstein, 1999; Sala, Signorelli, Barsuola, Bolognese, & Gobet, 2017; Prichard, Propper, & Christman, 2013).

  • Previous findings have shown that left-handed individuals tend to perform higher on verbal subtests, but lower on writing subtests than right-handed individuals (e.g., Halpern, Haviland, & Killian, 1998).

  • Non-dominant hand use on the Weschler Adult Intelligence Scale-III showed lower scores on the Digit-Symbol Coding and Symbol Search subtests than scores for standard administration (Ryan & Tree, 2007).

  • The literature has indicated that individuals who are left-handed take less time during some parts of cognitive testing (Gunstad, Spitznagel, Luyster, Cohen, & Paul, 2007).

  • It has been suggested that left-handed individuals must create special adaptations in order to adjust to environments that are designed to specifically accommodate individuals who are right-handed, evidenced by individuals who are left-handed displaying greater creativity (Newland, 1981).

  • The focus of previous research has not been on the effect of the design and layout of the test batteries that measure this construct, but minimal subtests (e.g., Coding on WISC-V) include specific instructions for left-handed individuals.

  • There is a need to consider design differences for subtests that require the tester to write responses due to the nature and direction in which left-handed individuals write and the layout for specific subtest designs.


  • How can the Weschler Intelligence Scale for Children-V guidelines for the Coding subtest (i.e., if a key is blocked with an individual’s left hand when completing items, administration should be stopped and an extra response booklet should be placed to the right of the individual) be applied to adaptations for other subtest administrations?

  • How can subtest design affect data interpretation in evaluation reports?

NASP 2020 Demo - Regular.pdf

Regular Format Demo

NASP 2020 Demo - Adapted.pdf

Adapted Format Demo


  • Examine time and performance differences between left-handed and right-handed individuals on specific Response Booklet subtests (Symbol Search on the Weschler Adult Intelligence Scale-IV and Silent Reading Fluency on the Kaufman Test of Educational Achievement-3), which could indicate a test bias in favor of individuals who are right-handed based on the design of the tests.
    Hypothesis 1: Right-handed individuals will correctly complete test items more quickly than left-handed individuals.

  • Examine if left-handed individuals would perform better on specific subtests if adaptations are made to better accommodate the way that left-handed individuals write and navigate the layout of the task.
    Hypothesis 2: With this accommodation, no significant difference between left-handed and right-handed individuals will be found.

Please check back in the future for the results of this study.


Ghayas, S., & Adil, A. (2007). Effect of handedness on intelligence level of students. Journal of the Indian Academy of Applied Psychology, 33(1), 85-91.

Gunstad, J., Spitznagel, M. B., Luyster, F., Cohen, R. A., & Paul, R. H. (2007). Handedness and cognition across the healthy lifespan. International Journal of Neuroscience, 117(4), 477-485.

Halpern, D. F., Haviland, M. G., & Killian, C. D. (1998). Handedness and sex differences in intelligence: Evidence from the Medical College Admission Test. Brain and Cognition, 38(1), 87-101.

Lamm, O., & Epstein, R. (1999). Left-handedness and achievements in foreign language studies. Brain and Language, 70(3), 504-517.

Newland, G. A. (1981). Differences between left-and right-handers on a measure of creativity. Perceptual and Motor Skills, 53(3), 787-792.

Peters, M., Reimers, S., & Manning, J. T. (2006). Hand preference for writing and associations with selected demographic and behavioral variables in 255,100 subjects: the BBC internet study. Brain and Cognition, 62(2), 177-189.

Prichard, E., Propper, R. E., & Christman, S. D. (2013). Degree of handedness, but not direction, is a systematic predictor of cognitive performance. Frontiers in Psychology, 4, 9.

Ryan, J. J., & Tree, H. A. (2007). Validity of WAIS-III performance scale subtests completed with the non-dominant hand. Applied Neuropsychology, 14(1), 52-55.

Sala, G., Signorelli, M., Barsuola, G., Bolognese, M., & Gobet, F. (2017). The relationship between handedness and mathematics is non-linear and is moderated by gender, age, and type of task. Frontiers in Psychology, 8, 948.

Stromberg, E. T., & Stromberg, E. L. (1938). Left Handedness as a Factor Influencing Academic Achievement. The Journal of Social Psychology, 9(3), 335-341.


For more information on this presentation, please contact Stephanie Miodus, M.A., M.Ed. at or Frank Farley, Ph.D. at