Heat and light in the childhood spanking debate

CMAJ 2000;162:765-6

See also response from H.L. MacMillan

Derryck Smith expresses discomfort with spanking but believes that it is necessary as a last resort. The idea that spanking works better than other corrective steps is not supported by the empirical evidence.^3,4,5,6,7 It is a cultural myth that distorts our perception of what actually happens in disciplinary encounters. The reality is that, even with normal toddlers, all methods of correction, including spanking, have a very high failure rate in the short run.⁶ But because of the cultural myth, when nonspanking modes of discipline are used and the almost inevitable repetition of the misbehaviour occurs, after 2 or 3 times parents conclude that this approach did not work and they have to spank. However, when the same almost inevitable repetition of the misbehaviour occurs after spanking, parents are prepared to spank over and over again until it does work. That actually is the right approach: consistency and persistence. What parents need to realize is that this approach is also needed with nonspanking modes of discipline. Thus, spanking is never necessary.

Although Kathy Lasell, Victoreia Foss, Arnita Lee and Teresa Leeth can be assumed to have accurately described the cases they mention, the main thing these cases show is that personal observation and common sense can be misleading. It is parallel to the situation with smoking. Most heavy smokers can say "I smoked all my life, and I'm fine." The implication that smoking is therefore harmless is false. Epidemiological research shows that 1 out of 3 heavy smokers (more than a pack a day) die from smoking-related diseases.⁸ This means that 2 out of 3 heavy smokers will not die of a smoking-related disease, hence most heavy smokers, like most people who have been spanked, will be able to point out that they are in good health.

Cross-national comparisons can also be misleading. Gabriel Leung points out that Asians believe that Asian "children grow up to become more successful than had they not been subject to such strict disciplinary practices [as spanking]." However, there are a host of other differences between Canada and Asian nations that could account for differences, if any, between the success of Asian and Canadian children.

If my call for an end to spanking had been based only on the study by Harriet MacMillan and colleagues, [full article]⁹ it would indeed have been "disturbing," as Lee Isaacs points out. But it was based on the accumulated evidence of over 80 studies (which, with rare exception, have found harmful long-term effects¹⁰) and especially the 5 recent prospective studies I cited in my editorial. No single study controlled all of the possible confounds (including various family demographic characteristics, parental role behaviours, characteristics of the child, and psychosocial problems of the parents) but those missed by one study were covered by others. It is a well-recognized scientific principle, sometimes called triangulation,¹¹ that one can come to valid conclusions on the basis of evidence from studies that, taken one by one, are not definitive. I think we have reached the point of triangulation concerning spanking.

Derryck Smith correctly says that with the research design used by MacMillan and colleagues, "one might conclude that children who inject insulin are more likely to have diabetes as adults." This problem was also pointed out by MacMillan and coworkers. The 5 prospective studies that I cited in my editorial, however, controlled for the presence of the disease (misbehaviour) at the time of the equivalent of the "injection" (spanking), and found that, on average, the long-term effect of the "injection" was to make the disease worse.

None of these 5 prospective studies depended on adults recalling childhood events, which addresses the concerns of Philip Whatley and Joel Paris about recall bias, and they all controlled for the fact that parents hit children who misbehave.

Joel Paris and Raymond Jacques feel that the link between spanking and mental health problems might reflect common genes. For this to explain the findings of MacMillan and colleagues on spanking, one has to assume that parents who spank are mentally ill. Moreover, assuming a genetic link of some type does not mean that learned behaviour and reactions to the way one is treated by others (such as being hit by a parent) are not also important.

I will conclude by suggesting a revision to the last sentence of Raymond Jacques' letter, which implies that there is appropriate spanking. To make the sentence consistent with the research evidence, it would have to read that a well-adjusted parent will never need to resort to spanking.

Murray A. Straus
Family Research Laboratory
University of New Hampshire
Durham, NH

Send a letter to the editor Envoyez une lettre à la rédaction

1. Straus MA. Beating the devil out of them: corporal punishment in American families. New York: Lexington Books; 1994. p. 157-9.
2. Straus MA. Is it time to ban corporal punishment of children? CMAJ 1999;161(7):821-2. [MEDLINE]
3. Day DE, Roberts MW. An analysis of the physical punishment component of a parent training program. J Abnorm Child Psychol 1983;11:141-52. [MEDLINE]
4. Larzelere RE, Sather PR, Schneider WN, Larson DB, Pike PL. Punishment enhances reasoning's effectiveness as a disciplinary response to toddlers. J Marriage Fam 1998;60:388-403.
5. LaVoie JC. Type of punishment as a determination of resistance to deviation. Dev Psychol 1974;10:181-9.
6. Larzelere RE, Schneider WN, Larson DB, Pike PL. The effects of discipline responses in delaying toddler misbehavior recurrences. Child Family Ther 1996;18:35-7.
7. Roberts MW, Powers SW. Adjusting chair timeout enforcement procedures for oppositional children. Behav Ther 1990;21:257-71.
8. Matteson ME, Pollack ES, Cullen JW. What are the odds that smoking will kill you? Am J Publ Health 1987;77:425-31.
9. MacMillan HL, Boyle MH, Wong MYY, Duku EK, Fleming JE, Walsh CA. Slapping and spanking in childhood and its association with lifetime prevalence of psychiatric disorders in a general population sample. CMAJ 1999;161(7):805-9. [MEDLINE]
10. Thompson EE. The short- and long-term effects of corporal punishment on children: a meta-analytic review. Psychol Bull. In press.
11. Webb EJ, Campbell DT, Schwartz RD, Sechrest L, Grove JB. Nonreactive measures in the social sciences. 2nd ed. Boston (Mass.): Houghton Mifflin Co.; 1981.

© 2000 Canadian Medical Association or its licensors