Mind the gap: MIND, the mental hygiene movement and the trapdoor in measurements of intellect.

van der Molen (2010) tells the story of how IQ tests were once used to label people with intellectual disability as mentally ill. The paper traces the early mental hygiene movement and shows how test scores became a trapdoor that dropped people into institutions.

The author uses old documents and past policies to build the case. No new data are collected; the goal is to warn modern clinicians about the dark side of testing history.

The review concludes that links between low IQ and mental health labels still fuel discrimination today. The historical pattern of using scores to deny rights has not fully gone away.

Frazier et al. (2023) picks up the story and offers a safer path. Their tribute to Ed Zigler shows how matching tasks to mental age, not calendar age, avoids the old trap that van der Molen (2010) describes. The newer paper extends the warning and gives a practical fix.

Parsons et al. (1993) shows the trap is real and measurable. Their data prove the PPVT inflates IQ scores in people with ID, echoing J’s point that tests can misrepresent ability. Together the two papers argue for caution when picking tools.

Brandsen et al. (2024) moves the risk into the digital age. They found that AI language models tag neurodivergent labels as more negative than criminal ones. The bias mirrors the historical discrimination van der Molen (2010) describes, only now it hides inside software.

Before you give any IQ test, pause and ask what the score will be used for. Choose tools that match mental age, not calendar age, and always explain limits in plain language to families. Check that your reports do not echo old ideas that low IQ equals mental illness or danger. If you use AI for scoring or report writing, audit it first to be sure it is not repeating hidden biases.