Spanking: What 75 Years of Research Shows Parents

In 2018, the American Academy of Pediatrics issued its clearest-ever statement against spanking. The statement wasn’t new science — it was a conclusion drawn from 75 years of accumulating research. If you’ve wondered what that research actually says — what it found, what it couldn’t prove, and what it means for how you handle a defiant 5-year-old — this summary is for it.

Key Takeaways

• Elizabeth Gershoff’s 2002 meta-analysis of 88 studies and 36,000+ children, updated in 2016 with 75 additional studies and over 160,000 children, found spanking associated with 13 negative outcomes and only 1 positive one (immediate compliance).
• The positive immediate compliance comes at measurable cost: the effect does not generalize — children who comply when spanked do not become more self-regulated; they become better at complying when threatened.
• Methodological limitations are real: most research is observational and cross-sectional, making causality difficult to establish definitively.
• The AAP’s 2018 policy statement recommends eliminating all forms of physical punishment based on the current evidence base.
• Several discipline alternatives have stronger research support: positive reinforcement, logical consequences, and collaborative problem-solving all show better long-term outcomes for moral internalization.

The Research: What Two Generations of Studies Show

Elizabeth Gershoff (University of Texas at Austin) conducted the field’s most comprehensive review. Her 2002 paper in Psychological Bulletin synthesized 88 studies from six decades, examining 11 child outcomes associated with corporal punishment.

Her 2016 update with Andrew Grogan-Kaylor (University of Michigan), published in Journal of Family Psychology, added a stronger methodological filter — requiring longitudinal designs where possible — and reached 160,000+ children across 75 studies.

What the research associates with spanking:

Outcome	Association with Spanking	Effect Size
Immediate compliance	Positive (short-term)	Moderate
Moral internalization	Negative	Small-moderate
Aggression	Increased	Moderate
Antisocial behavior	Increased	Small-moderate
Mental health problems	Increased	Small-moderate
Cognitive ability (IQ proxy)	Decreased	Small
Self-esteem	Decreased	Small
Parent-child relationship quality	Decreased	Moderate
Physical abuse risk	Increased	Moderate-large

The most consistent finding: spanking predicts increased aggression, not decreased aggression. The effect appears to be bidirectional — more aggressive children may elicit more spanking, and spanking may increase aggression — but longitudinal studies controlling for baseline aggression still find the association.

The Methodological Caveats

Gershoff herself has been explicit about the limitations of this literature, which critics have sometimes overlooked:

1. Most research is observational and cross-sectional — it shows correlation, not proven causation. Parents who spank differ from parents who don’t in many ways beyond spanking itself.

2. Selection effects are hard to fully control for — children who receive more spanking also tend to have higher temperamental difficulty, which independently predicts several of the same negative outcomes.

3. Severity and context are poorly captured — an occasional swat on the hand during a dangerous situation may have different effects than routine belt-spanking, but most studies do not distinguish these.

4. Publication bias likely inflates findings — studies that find no effect are published less often.

These caveats matter. They mean the effect sizes in the research should be interpreted cautiously, and that “spanking causes X” is a stronger claim than the research strictly supports. What the research supports is: spanking predicts these outcomes even after controlling for many confounders, across dozens of independent studies, in multiple countries.

Robert Larzelere (Oklahoma State) has long argued that “conditional spanking” — two smacks on the bottom, used rarely and specifically for defiant behavior in young children, as a backup to other strategies — does not show the same effects as frequent or severe corporal punishment. This remains a minority position in the literature.

The Cultural and Religious Context

Corporal punishment rates differ dramatically by cultural and religious context. Research by Ellison and Bradshaw (2009, Journal of Family Issues) found that conservative Protestant theology predicting biblical literalism was among the strongest predictors of corporal punishment endorsement in the U.S.

Cross-cultural research shows that in societies where corporal punishment is the normative expectation, the peer victimization that sometimes mediates the aggression finding is reduced (Lansford et al., 2005, Child Development). This suggests some of the harm from spanking is mediated through stigma and the signal it sends about adult-child relationships in that context — not exclusively through the pain itself.

What the AAP’s 2018 Statement Actually Says

The American Academy of Pediatrics’ 2018 policy statement (Pediatrics, 142(6)) recommended that pediatricians:

• Counsel parents to eliminate spanking, slapping, and hitting
• Recognize that verbal threats and humiliation cause similar harm
• Teach parents alternative strategies proactively, not just reactively

Critically, the statement distinguished between “mild” and “severe” corporal punishment but recommended elimination of all forms because of the evidence of potential harm and absence of evidence of unique benefit — the AAP position is precautionary in the face of a tilted evidence base.

What Actually Works Better

The discipline alternatives with the strongest research support:

Positive reinforcement — Catching appropriate behavior and acknowledging it specifically increases compliance more durably than punishment. Research by Forehand and McMahon (1981, Helping the Noncompliant Child) found that parents trained in positive attention saw larger compliance improvements than parents trained in punishment strategies.

Logical and natural consequences — Connecting the consequence to the behavior (you didn’t put away the bike, so the bike stays inside tomorrow) produces better moral internalization than arbitrary punishment because the child can understand the causal relationship.

Collaborative problem-solving — Ross Greene’s research (discussed in our piece on natural consequences vs. punishment) shows that involving children in generating solutions to repeated behavior problems produces better compliance and fewer explosive episodes than top-down discipline.

Planned ignoring + consistent follow-through — For attention-maintained behavior, planned ignoring combined with predictable consequences for boundary-crossing reduces escalation cycles.

What to Watch For Over the Next 3 Months

Month 1: Notice what triggers your impulse to spank or threaten physical consequences. Research by Patterson (1982) on coercive cycles shows that physical punishment impulses typically arise after an escalation sequence that could be interrupted earlier — not after the first misbehavior.

Month 2: Identify one replacement strategy for the triggers you identified. If spanking was your backup for defiance, practice a pre-announced calm-down consequence: “If you do X again, Y will happen, and I will not debate it.” Then follow through without escalation.

Month 3: Assess whether you’re using discipline consistently enough for your child to predict it. Research on punishment effectiveness shows that predictability matters more than severity — an inevitable mild consequence is more behavior-changing than an occasional severe one.

For more on how discipline connects to brain development and stress responses, see our piece on how stress hormones affect kids’ learning.

Frequently Asked Questions

If spanking is so harmful, why do most adults who were spanked turn out fine?

Most outcomes in developmental psychology are probabilistic, not deterministic. Occasional spanking in an otherwise warm, stable family increases certain risk probabilities slightly — it does not guarantee harm. “Turning out fine” is also a low bar; the research tracks specific outcomes like aggression, mental health scores, and academic achievement — not just overall adult function.

What should I do when nothing else works with my 3-year-old?

Research supports that most 3-year-old defiance responds to: clear, simple warnings (one, not three); predictable follow-through on small consequences; and high levels of positive attention when the child is behaving well. When “nothing works,” the most common issue is inconsistent follow-through combined with inadvertent reinforcement of the defiant behavior through negotiation.

Is a single spank as damaging as regular spanking?

The research does not show a threshold below which there is zero risk, but effect sizes in the literature are driven by frequency. A single, isolated spank in an otherwise warm, engaged family is unlikely to cause lasting harm. The concern in the research is with spanking as a regular discipline tool — used repeatedly and as a first resort.

What does the research say about timeouts?

Timeouts have a strong evidence base when used correctly: brief (roughly one minute per year of age), calm (not used in anger), and followed by a reconnection. Research shows they work primarily as a removal of parental attention and stimulation, not as punishment. They lose effectiveness when they become battles over entering/staying in timeout — at that point, the struggle itself becomes the attention reinforcement.

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About the author

Ricky Flores is the founder of HiWave Makers and an electrical engineer with 15+ years of experience building consumer technology at Apple, Samsung, and Texas Instruments. He writes about how kids learn to build, think, and create in a tech-saturated world. Read more at hiwavemakers.com.

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Sources

1. Gershoff, E. T. (2002). Corporal punishment by parents and associated child behaviors and experiences. Psychological Bulletin, 128(4), 539–579. https://doi.org/10.1037/0033-2909.128.4.539
2. Gershoff, E. T., & Grogan-Kaylor, A. (2016). Spanking and child outcomes: Old controversies and new meta-analyses. Journal of Family Psychology, 30(4), 453–469. https://doi.org/10.1037/fam0000191
3. American Academy of Pediatrics. (2018). Effective discipline to raise healthy children. Pediatrics, 142(6), e20183112. https://doi.org/10.1542/peds.2018-3112
4. Lansford, J. E., Chang, L., Dodge, K. A., Malone, P. S., Oburu, P., Palmérus, K., … & Quinn, N. (2005). Physical discipline and children’s adjustment: Cultural normativeness as a moderator. Child Development, 76(6), 1234–1246.
5. Larzelere, R. E., & Kuhn, B. R. (2005). Comparing child outcomes of physical punishment and alternative disciplinary tactics. Clinical Child and Family Psychology Review, 8(1), 1–37.
6. Patterson, G. R. (1982). Coercive Family Process. Castalia Publishing.
7. Centers for Disease Control and Prevention. (2022). Child abuse and neglect prevention. https://www.cdc.gov/violenceprevention/childabuseandneglect/