LARZELERE & BAUMRIND 10/12/2010 11:54:42 AM ARE SPANKING INJUNCTIONS
SCIENTIFICALLY SUPPORTED?
ROBERT E. LARZELERE*
DIANA BAUMRIND**
I
INTRODUCTION
This special issue on corporal punishment addresses arguments for and
against prohibitions of the historically widespread practice of disciplinary
spanking by parents. A recent national survey estimated that ninety-four
percent of American parents of four- and five-year-olds spanked their children
at least occasionally.1 Yet there is a growing trend for countries to ban corporal
punishment by parents through family law or criminal law.2 This article
evaluates whether the current empirical evidence supports spanking
prohibitions.
Does the scientific evidence show that spanking is invariably detrimental
regardless of how it is used? Or can parents use spanking in nonharmful or
beneficial ways, at least under some conditions? Should all corporal punishment
be enjoined, or should a legal distinction be retained between spanking and
physical abuse? These crucial questions compare the validity of two scientific
perspectives, “anticorporal punishment” and “conditional corporal
punishment,”3 both of which are represented in this issue.4 In this article, we will Copyright © 2010 by Robert E. Larzelere and Diana Baumrind.
This article is also available at http://www.law.duke.edu/journals/lcp.
* Department of Human Development and Family Science, Oklahoma State University.
** Institute of Human Development, University of California, Berkeley.
1. Murray A. Straus & Julie H. Stewart, Corporal Punishment by American Parents: National
Data on Prevalence, Chronicity, Severity, and Duration, in Relation to Child and Family Characteristics,
2 CLINICAL CHILD & FAM. PSYCHOL. REV. 55, 59–60 (1999).
2. See Legal Reforms, CENTER FOR EFFECTIVE DISCIPLINE, http://www.stophitting.com/
index.php?page=laws-main (last visited January 6, 2010).
3. Corina Benjet & Alan E. Kazdin, Spanking Children: The Controversies, Findings, and New
Directions, 23 CLINICAL PSYCHOL. REV. 197, 200–01 (2003). This article compared two recent
literature reviews representing those two perspectives, one by Elizabeth Thompson Gershoff, Corporal
Punishment by Parents and Associated Child Behaviors and Experiences: A Meta-Analytic and
Theoretical Review, 128 PSYCHOL. BULL. 539 (2002), and the other by Robert E. Larzelere, Child
Outcomes of Nonabusive and Customary Physical Punishment by Parents: An Updated Literature
Review, 3 CLINICAL CHILD & FAM. PSYCHOL. REV. 199 (2000).
4. Elizabeth T. Gershoff, More Harm Than Good: A Summary of Scientific Research on the
Intended and Unintended Effects of Corporal Punishment on Children, 73 LAW & CONTEMP. PROBS. 57
(Spring 2010). LARZELERE & BAUMRIND 58 10/12/2010 11:54:42 AM LAW AND CONTEMPORARY PROBLEMS [Vol. 73:57 use the terms spanking prohibition and conditional spanking to differentiate
these two positions. The conditional-spanking viewpoint holds that spanking
may be an appropriate disciplinary option under some conditions but not
others. The conditions under which spanking may be a viable disciplinary
method need to be investigated before applying a blanket prohibition. Because
advocates of both positions are opposed to overly severe and abusive corporal
punishment,5 evidence about the effects of excessively severe punishment does
not differentiate the two positions and is not directly relevant to the desirability
of spanking prohibitions. Evidence about using corporal punishment too
severely would be indirectly relevant, however, if it could be shown that a
spanking prohibition and conditional spanking differ in their abilities to prevent
disciplinary actions from escalating to physical abuse, an issue addressed in
section V.
Spanking-prohibition and conditional-spanking positions differ, too, on
whether the use of disciplinary spanking is always or generally harmful in a
cost-benefit analysis. The spanking-prohibition viewpoint necessarily implies
that any nonharmful or beneficial subset of parental corporal punishment is so
small a proportion or so minor in its benefits that it is outweighed by the
detrimental effects of retaining any spanking option for parents.
To justify removing this option from parents, spanking prohibitionists first
need to show causal evidence that spanking is detrimental in situations where it
is considered most appropriate by parents, children, and psychologists.6 Second,
prohibitionists need to compare the effects of spanking with the effects of
alternative disciplinary tactics available to parents in the same disciplinary
situations. Third, prohibitionists need evidence that parenting improves when
parents are prevented from using disciplinary spanking. Fourth, prohibitionists
need to show that adverse outcomes associated with spanking remain associated
with spanking after eliminating the influences of several prevalent confounding
variables, such as difficult child temperaments and socioeconomic
disadvantages. If these confounding factors together account for the
associations between spanking and adverse outcomes, those associations would
be spurious and therefore misinterpreted as causal influences of spanking.
It is well known that children thrive under authoritative parenting,7 recently
confirmed by ten-year outcomes from Baumrind’s classic longitudinal data.8
Authoritative parenting combines nurturance, give-and-take communication, 5. Benjet & Kazdin, supra note 3, at 202.
6. Thomas F. Catron & John C. Masters, Mothers’ and Children’s Conceptualizations of Corporal
Punishment, 64 CHILD DEV. 1815, 1819 (1993); Mark W. Roberts & Scott W. Powers, Adjusting Chair
Timeout Enforcement Procedures for Oppositional Children, 21 BEHAV. THERAPY 257, 262 (1990).
7. Ross D. Parke & Raymond Buriel, Socialization in the Family: Ethnic and Ecological
Perspectives, in 3 HANDBOOK OF CHILD PSYCHOLOGY: SOCIAL, EMOTIONAL, AND PERSONALITY
DEVELOPMENT 429, 436–37 (W. Damon et al. eds., 2006); Laurence Steinberg, We Know Some Things:
Parent-Adolescent Relationships in Retrospect and Prospect, 11 J. RES. ON ADOLESCENCE 1, 1 (2001).
8. Diana Baumrind et al., Effects of Preschool Parents’ Power Assertive Patterns and Practices on
Adolescent Development, 10 PARENTING: SCI. & PRAC. 167 (2010). LARZELERE & BAUMRIND Spring 2010] 10/12/2010 11:54:42 AM ARE SPANKING INJUNCTIONS SCIENTIFICALLY SUPPORTED? 59 and support for age-appropriate independence with firm, confrontive discipline
and maturity demands. It is critically distinguishable from authoritarian
parenting, which is equally firm but shares none of the other aspects of
authoritative parenting and is characterized instead by the use of hostile verbal
discipline and severe corporal punishment. On average, authoritative parents
spanked just as much as the average of all other parents.9 Undoubtedly, some
parents can be authoritative without using spanking, but we have no evidence
that all or even most parents can achieve authoritative parenting without an
occasional spank. A crucial question is whether spanking prohibitions would
undermine authoritative parenting for some parents. Would parents then use
nonphysical disciplinary tactics more effectively than if they retained the
spanking option? Or would parents enjoined from spanking become like
authoritarian parents in using more verbal hostility, which is more detrimental
than spanking,10 or, like permissive parents, become less able to enforce
appropriate child cooperation? Permissive parents are nurturant and support
age-appropriate independence but tend to avoid disciplinary confrontations and
make few demands for mature responsibility and cooperation. Children of
authoritarian parents were far less competent ten years later compared to
children of authoritative parents, whereas children of permissive parents were
the second least-competent group.11
This article summarizes the scientific evidence on child outcomes of
spanking, emphasizing causal evidence under conditions considered most
appropriate for its use by parents and psychologists. Section II discusses the
distinctions that must be made to answer crucial questions about the effects of
spanking under those conditions. With those distinctions in mind, section III
then contrasts two major literature reviews on corporal punishment. Section IV
starts by summarizing the few definitive studies that have made all of the
necessary distinctions outlined in section II and then summarizes and critiques
the strongest causal evidence against ordinary spanking. Section V addresses
other empirical issues, including the role of spanking in escalations of
disciplinary actions toward abuse, the aversiveness of spanking compared to
alternatives, and ethnic differences in the apparent outcomes of spanking.
Section VI presents our conclusions.
II
NECESSARY DISTINCTIONS
Scientific support for injunctions against parents’ use of disciplinary
spanking must document that nonabusive spanking is harmful or ineffective
when parents perceive the greatest need to use it—for example, when young
children are persistently defiant even after parents try other disciplinary actions. 9. Id. at 179, 187.
10. Id. at 157, 178–83.
11. Id. at 157, 172–76, 84. LARZELERE & BAUMRIND 60 10/12/2010 11:54:42 AM LAW AND CONTEMPORARY PROBLEMS [Vol. 73:57 To be relevant for spanking prohibitions, empirical evidence must come
from studies that discriminate three crucial issues correctly: (1) Corporal
punishment must be implemented nonabusively (correct dosage), (2) it must be
used in an appropriate disciplinary situation (appropriate presenting problems),
and (3) the evidence must be causal, not correlational. Prohibitions of
corrective medical actions would not be considered unless evidence came from
studies making all three distinctions correctly. For example, a prohibition
against radiation treatment would first need to show causal evidence of harm
from appropriate dosages administered for appropriate presenting problems.
A. Appropriate Dosage
Any prohibition against spanking must likewise rely on evidence from
nonabusive implementation, rather than evidence based on lumping spanking
together with overly severe corporal punishment. The 1996 scientific-consensus
conference on The Short- and Long-Term Consequences of Corporal
Punishment defined corporal punishment as “bodily punishment of any kind as
a form of discipline”12 and spanking as a kind of corporal punishment that is “a.
physically non-injurious; b. intended to modify behavior; and c. administered
with an opened hand to the extremities or buttocks.”13 This article adopts this
definition of spanking, which limits it to nonabusive usage, differentiated from
severe corporal punishment.
To justify spanking prohibitions, research must first show the detrimental
causal effects of spanking and then that less extreme injunctions cannot
minimize those detrimental effects. Moreover, a cost-benefit analysis must
weigh any unavoidable detrimental effects against any beneficial effects found
for spanking. Radiation therapy has negative side effects, but it would not be
prohibited unless studies showed that alternative treatments produced
consistently better outcomes without increasing negative side effects, based on
causal evidence of appropriate applications of radiation. In this article we will
show that corporal punishment is associated with more-adverse outcomes than
alternative disciplinary tactics only for severe and predominant use of corporal
punishment.
B. Appropriate Presenting Problems
Just as radiation treatments are evaluated for specific types of cancer,
spanking needs to be evaluated for its most appropriate presenting problems.
Two kinds of evidence are relevant: situations in which parents are most likely
to spank and situations in which psychologists have trained parents of young
children when to spank appropriately. First, parents are most likely to spank 12. Stanford B. Friedman & S. Kenneth Schonberg, Consensus Statements, 98 PEDIATRICS 853, 853
(1996).
13. Id. LARZELERE & BAUMRIND Spring 2010] 10/12/2010 11:54:42 AM ARE SPANKING INJUNCTIONS SCIENTIFICALLY SUPPORTED? 61 one- to nine-year-olds14 for defiance,15 especially when their misbehavior hurts
someone else16 or puts the children themselves in danger.17 Second, from the late
1960s18 until the middle 1990s, clinical psychologists trained parents to use
spanking19 to enforce time-out compliance in behavioral parent training
programs for young children with disruptive-behavior diagnoses.20 Two
prominent practitioners in that period explained, “While we basically are
opposed to physical punishment, we have found a mild spanking to be the most
feasible backup for the child leaving the [time-out] chair.”21 These behavioral
parent training programs—which feature time-out currently enforced with an
alternative back-up—are currently recognized as some of the most effective
treatments for young children with attention deficit–hyperactivity disorder
(ADHD),22 oppositional defiant disorder, and conduct disorder.23 We will show
that the strongest causal evidence about spanking indicates that it is effective
for reducing defiance in the most defiant two- to six-year-olds, which is crucial
for their cooperation with time-out. The few other studies that focus on
defiance or dangerous behaviors also document better outcomes for spanking
than for most alternative tactics when dealing with defiance in young children.
C. Causal vs. Correlational Evidence
Corporal punishment is usually correlated with behavior problems such as
antisocial behavior and aggression.24 But correlation does not equal causation.
What is open to dispute are the causal influences that explain those
correlations. Making valid causal conclusions from correlations involving
corrective actions is especially problematic, for correlations are biased against 14. Straus & Stewart, supra note 1, at 59.
15. Kathy L. Ritchie, Maternal Behaviors and Cognitions During Discipline Episodes: A
Comparison of Power Bouts and Single Acts of Noncompliance, 35 DEVELOPMENTAL PSYCHOL. 580,
587 (1999).
16. George W. Holden et al., Why 3-Year-Old Children Get Spanked—Parent and Child
Determinants as Reported by College-Educated Mothers, 41 MERRILL-PALMER Q.: J.
DEVELOPMENTAL PSYCHOL. 431, 441 (1995).
17. Catron & Masters, supra note 6, at 1817, 1819–20; Ritchie, supra note 15, at 587.
18. TONI L. HEMBREE-KIGIN & CHERYL B. MCNEIL, PARENT–CHILD INTERACTION THERAPY 2
(1995).
19. Id. at 94–95; RUSSELL A. BARKLEY, DEFIANT CHILDREN: A CLINICIAN’S MANUAL FOR
PARENT TRAINING 117–18 (1987); EDWARD R. CHRISTOPHERSEN, LITTLE PEOPLE: GUIDELINES FOR
COMMON SENSE CHILD REARING 151 (3d ed. 1988); REX L. FOREHAND & ROBERT J. MCMAHON,
HELPING THE NONCOMPLIANT CHILD 79–80 (1981).
20. BARKLEY, supra note 19, at 2–3; CHRISTOPHERSEN, supra note 19, at 50, 152; FOREHAND &
MCMAHON, supra note 19, at ix; HEMBREE-KIGIN & MCNEIL, supra note 18, at 7.
21. FOREHAND & MCMAHON, supra note19, at 80.
22. William E. Pelham, Jr. & Gregory A. Fabiano, Evidence-Based Psychosocial Treatments for
Attention-Deficit/Hyperactivity Disorder, 37 J. CLINICAL CHILD & ADOLESCENT PSYCHOL. 184, 187
(2008).
23. Sheila M. Eyberg et al., Evidence-Based Psychosocial Treatments for Children and Adolescents
with Disruptive Behavior, 37 J. CLINICAL CHILD & ADOLESCENT PSYCHOL. 215, 226–29 (2008).
24. This is so both cross-sectionally and longitudinally. Gershoff, supra note 3, at 539. LARZELERE & BAUMRIND 62 10/12/2010 11:54:42 AM LAW AND CONTEMPORARY PROBLEMS [Vol. 73:57 corrective actions, a problem known as the intervention selection bias.25 This
selection bias occurs because of the poorer prognosis of those selected for the
corrective action compared to the better prognosis of those not needing the
corrective action.
To illustrate this bias, Table 1 summarizes data from the largest study of
radiation treatment for Stage II endometrium cancer prior to 1992.26 Women
who received radiation treatment had a higher probability of dying in the next
five years than did women of the same age in the general population. Either
type of radiation treatment was therefore correlated with a higher rate of dying
compared to women of the same age who did not receive radiation treatment.
Using the program employed by Gershoff27 to calculate effect-size statistics, this
translates to large detrimental effect sizes of d = .61 and d = 1.80 for the two
treatments.28 By comparison, Gershoff’s effect sizes for adverse outcomes of
physical punishment ranged from d = .09 to d = .69,29 which therefore appear
less adverse than the radiation treatments in Table 1 when their effect size
statistics are based inappropriately on unadjusted correlations. This shows that
effect sizes based on longitudinal correlations are biased against all corrective
actions because the comparison group includes many who did not need any
corrective action. In the same way that having cancer causes women to be more
likely to receive radiation treatment, children’s oppositional behavior causes
parents to be more likely to use all disciplinary tactics more frequently, not just
spanking. Therefore the frequencies of all disciplinary tactics are correlated
with more disruptive-behavior problems twenty months later, an association not
distinctive of spanking.30 25. Robert E. Larzelere et al., The Intervention Selection Bias: An Underrecognized Confound in
Intervention Research, 130 PSYCHOL. BULL. 289, 289 (2004).
26. Perry W. Grigsby et al., Stage II Carcinoma of the Endometrium: Results of Therapy and
Prognostic Factors, 11 INT’L J. RADIATION ONCOLOGY BIOLOGY PHYSICS 1915, 1918 (1985).
27. Gershoff, supra note 3, at 544.
28. Effect sizes in d estimate the difference a treatment is expected to make in terms of standard
deviations of the outcome variable. In the social sciences, an effect size of d = .20 is considered small, d
= .50 medium, and d = .80 large. JACOB COHEN, STATISTICAL POWER ANALYSIS FOR THE
BEHAVIORAL SCIENCES 25–26 (2d ed. 1988).
29. Gershoff, supra note 3, at 547.
30. Larzelere, supra note 25, at 290–91; Robert E. Larzelere et al., Punishment Enhances
Reasoning’s Effectiveness as a Disciplinary Response to Toddlers, 60 J. MARRIAGE & FAM. 388, 400
(1998). LARZELERE & BAUMRIND Spring 2010] 10/12/2010 11:54:42 AM ARE SPANKING INJUNCTIONS SCIENTIFICALLY SUPPORTED? 63 Table 1. Five-Year Survival Rates for Stage II Endometrial Carcinoma
Treatment (or 5-year Survival Rate 5-year Death Rate a Equivalent
b Comparison Effect Sizes Condition) r Radiation plus surgery 78% d 22% .29 .61 Radiation alone 48% 52% .67 1.81 Actuarial survival, 65- 93% 7% -- -- c year-old women
a 31 32 Based on Grigsby et al., the largest study of Stage II Endometrial Cancer in Glassburn et al. b 33 Compared to actuarial survival in 65-year-old American women, using the statistical program
34 used in Gershoff’s meta-analysis to calculate effect sizes.
c 35 Based on 65-year-old American women, just above the median age of patients in Grigsby et al. In summarizing the relevant empirical literature, then, it is important to
distinguish correlational evidence from causally definitive and causally relevant
results. Causally definitive results are those based on the kinds of randomized
clinical trials that are widely recognized in science as providing more conclusive
causal evidence than any other research strategy.36 Because findings from
randomized clinical trials are recognized as causally definitive, they are required
by the Federal Drug Administration for new prescription drugs and by the
Society of Clinical Child and Adolescent Psychology37 to identify “evidencebased” psychosocial treatments for children and adolescents.38 Causally relevant
refers to studies that provide stronger causal evidence than unadjusted
correlations yet do not use the randomization methods required for causally
definitive conclusions. The most relevant example involves studies in which
corporal punishment predicts a subsequent child outcome even after adjusting
statistically for preexisting differences in that outcome, a research strategy 31. Grigsby et al., supra note 26, at 1918.
32. J. R. Glassburn et al., Endometrium, in PRINCIPLES AND PRACTICE OF RADIATION
ONCOLOGY 1203, 1214–15 (C. A. Perez & L. W. Brady eds., 1992).
33. BLAIR T. JOHNSON, DSTAT: SOFTWARE FOR THE META-ANALYTIC REVIEW OF RESEARCH
LITERATURE (1989).
34. Gershoff, supra note 3, at 544.
35. Grigsby et al., supra note 26, at 1916.
36. WILLIAM R. SHADISH, THOMAS D. COOK, & DONALD T. CAMPBELL, EXPERIMENTAL AND
QUASI-EXPERIMENTAL DESIGNS FOR GENERALIZED CAUSAL INFERENCE 13 (2002).
37. The Society of Clinical Child and Adolscent Psychology is the fifty-third division of the
American Psychological Association. See Divisions, AM. PSYCHOL. ASS’N, (Sept. 6, 2010), http://
www.apa.org/about/division/index.aspx.
38. Wendy K. Silverman & Stephen P. Hinshaw, The Second Special Issue on Evidence-Based
Psychosocial Treatments for Children and Adolescents, 37 J. CLINICAL CHILD & ADOLESCENT
PSYCHOL. 1, 5 (2008). LARZELERE & BAUMRIND 64 10/12/2010 11:54:42 AM LAW AND CONTEMPORARY PROBLEMS [Vol. 73:57 known as net-effects regression.39 Such statistical adjustments yield unbiased
estimates of causal effects only when the process of selecting recipients for a
corrective action is measured comprehensively40 and without measurement
error.41 Accordingly, epidemiologists recognize that residual confounding
remains when confounds are only partially controlled for statistically.42 We will
show that residual confounding can easily account for the strongest causal
evidence against spanking.
D. Other Methodological Issues
Three other pervasive methodological issues warrant brief mention: (1)
same-source bias, (2) confounding ineffectiveness with spanking frequency, and
(3) the fact that very few studies have compared spanked children with neverspanked children. First, same-source bias occurs when the same person (for
example, a parent) is the source of information for measures of spanking and of
the child outcome. A mother who just told an interviewer that she spanks her
son frequently might try to justify it later in the interview by exaggerating her
son’s belligerence. Accordingly, same-source bias is known to artificially
increase correlations of disciplinary tactics with adverse child outcomes, such as
aggression.43 Second, the more effectively any disciplinary tactic is used, the less
need there will be to use it in the future. Therefore, frequency of a disciplinary
tactic is partly due to how ineffectively a parent has used it previously, with
more-effective implementations resulting in lower frequencies. This bias can
make any disciplinary tactic appear to be more detrimental than it is, when
based on measures of frequency of use.
Third, very few studies have actually compared a spanked group to a neverspanked one; most studies contrast frequent spanking with infrequent spanking.
For example, the statistically controlled studies with the strongest causal
evidence against customary spanking are all based on spanking frequency in the
past week. Parents who spanked less than every other week would most likely
be lumped together with never-spankers in the no-spanking group for that
particular week. 39. A relevant example of net effects regression is the association between spanking at an initial
time and aggression a year later, after removing what can be predicted about that aggression a year
later from initial levels of aggression (that is, net of what can be predicted from initial aggression
levels). Stephen Turner, “Net Effects”: A Short History, in CAUSALITY IN CRISIS? STATISTICAL
METHODS AND THE SEARCH FOR CAUSAL KNOWLEDGE IN THE SOCIAL SCIENCES 23–25 (Vaughn R.
McKim & Stephen P. Turner eds., 1997).
40. James J. Heckman, Sample Selection Bias as a Specification Error, 47 ECONOMETRICA 153, 160
(1979).
41. DONALD T. CAMPBELL & DAVID A. KENNY, A PRIMER ON REGRESSION ARTIFACTS 155
(1999); David A. Freedman, Statistical Models and Shoe Leather, 21 SOC. METHODOLOGY 291, 302–04
(1991).
42. KENNETH J. ROTHMAN & SANDER GREENLAND, MODERN EPIDEMIOLOGY 62, 255–59 (2d
ed. 1998).
43. MARIAN R. YARROW ET AL., CHILD REARING: AN INQUIRY INTO RESEARCH AND
METHODS 80 (1968). LARZELERE & BAUMRIND Spring 2010] 10/12/2010 11:54:42 AM ARE SPANKING INJUNCTIONS SCIENTIFICALLY SUPPORTED? 65 III
MAJOR LITERATURE REVIEWS
Of the six reviews of studies of corporal punishment published between
1996 and 2005,44 only Gershoff45 supports a spanking prohibition. Paolucci and
Violato emphasized that the associations between corporal punishment and
affective, cognitive, or behavioral child outcomes were very small,46 concluding
that the patterns of the causal evidence “seem to support Larzelere’s . . .
contention that it is premature to impose guilt on the majority of parents who
use ordinary span...

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