Assessment & Research

Standard of practice and Flynn Effect testimony in death penalty cases.

Gresham et al. (2011) · Intellectual and developmental disabilities 2011
★ The Verdict

Always Flynn-correct outdated IQ scores in Atkins evaluations or your report may be invalid.

✓ Read this if BCBAs who conduct or review IQ assessments for capital cases.
✗ Skip if Clinicians who only work with children in schools or clinics.

01Research in Context

01

What this study did

The authors looked at how courts use old IQ scores in death-penalty cases. They asked: do we need to fix those scores for the Flynn Effect?

They read legal and psychology journals. They wrote a narrative review. Their goal was to set a clear standard for evaluators.

02

What they found

Uncorrected IQ scores can mislabel a person. That mistake can send someone with intellectual disability to execution.

The paper says you must apply Flynn corrections. If you do not, your report fails both ethical and professional standards.

03

How this fits with other research

Lichten et al. (2007) came first. They told evaluators to allow a 10-point margin of error around any IQ score. Amore et al. (2011) keep that margin but add the Flynn fix. Together they give a tighter, fairer rule.

Greenspan (2011) shows the human cost. His case study of Joe Arridy proves wrongful execution can happen when IQ labels are wrong. The new review gives a tool to stop that.

Fujiura (2012) and Tavassoli et al. (2012) echo the same theme: adapt your tests to the person’s mind. M et al. do this for IQ scores in court, the others for health or research settings.

04

Why it matters

If you ever review IQ scores for court, always check the test date. Apply the Flynn table before you write the number. State the corrected score and the margin of error. This single step can keep your report ethical, legal, and fair.

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→ Action — try this Monday

Add a Flynn lookup table to your forensic template and use it on every pre-2010 IQ score.

02At a glance

Intervention
not applicable
Design
narrative review
Population
not specified
Finding
not reported

03Original abstract

The Flynn Effect is a well-established psychometric fact documenting substantial increases in measured intelligence test performance over time. Flynn's (1984) review of the literature established that Americans gain approximately 0.3 points per year or 3 points per decade in measured intelligence. The accurate assessment and interpretation of intellectual functioning becomes critical in death penalty cases that seek to determine whether an individual meets the criteria for intellectual disability and thereby is ineligible for execution under Atkins v. Virginia (2002) . We reviewed the literature on the Flynn Effect and demonstrated how failure to adjust intelligence test scores based on this phenomenon invalidates test scores and may be in violation of the Standards for Educational and Psychological Testing as well as the "Ethical Principles for Psychologists and Code of Conduct." Application of the Flynn Effect and score adjustments for obsolete norms clearly is supported by science and should be implemented by practicing psychologists.

Intellectual and developmental disabilities, 2011 · doi:10.1352/1934-9556-49.3.131