NotesFAQContact Us
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ897708
Record Type: Journal
Publication Date: 2010-Oct
Pages: 13
Abstractor: As Provided
Reference Count: 31
ISSN: ISSN-0734-2829
Peeking inside the "Black Box" of the Flynn Effect: Evidence from Three Wechsler Instruments
Zhou, Xiaobin; Zhu, Jianjun; Weiss, Lawrence G.
Journal of Psychoeducational Assessment, v28 n5 p399-411 Oct 2010
This study investigated the Wechsler Performance IQ (PIQ) or Perceptual Reasoning Index (PRI)/ Perceptual Organization Index (POI) change over time and its relation to ability levels. PIQ or PRI/ POI was analyzed because of the known sensitivity of nonverbal scales to the Flynn effect. Scores were analyzed using two methods. First, analysis of covariance was applied to the combination of four representative samples of individuals who were administered the following pairs of Wechsler batteries in counterbalanced order: "Wechsler Preschool and Primary Scale of Intelligence-Revised" (WPPSI-R) and WPPSI-III (N = 174), "Wechsler Intelligence Scale for Children-Third Edition" (WISC-III) and WISC-IV (N = 239), "Wechsler Adult Intelligence Scale-Revised" (WAIS-R) and WAIS-III (N = 191), and WAIS-III and WAIS-IV ( N = 240). Second, equal percentile equating was applied to each of the samples independently. Although the two methods produced different patterns of results, both methods showed some evidence of variation in the magnitude of the Flynn effect across ability levels. These results call into question the practice of adjusting IQs based on an average expected Flynn effect in routine clinical evaluations. (Contains 3 tables and 6 figures.)
SAGE Publications. 2455 Teller Road, Thousand Oaks, CA 91320. Tel: 800-818-7243; Tel: 805-499-9774; Fax: 800-583-2665; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Assessments and Surveys: Wechsler Adult Intelligence Scale; Wechsler Intelligence Scale for Children; Wechsler Preschool and Primary Scale of Intelligence