Some of the Major Methodological Limitations,

Issues, Concerns, and Controversies

1. Correlation does not establish cause.

The popular and scientific literature is rife with spurious correlation. And each side of this issue charges the other side with exactly that.

"A generative model of causation at a minimum must establish that the association between corporal punishment and a specific negative outcome in a given population is consistent, strong, specific, temporally prior, and theoretically coherent." (Diana Baumrind, Oct 1996)

"By unambiguous evidence, we require longitudinal investigation with appropriate controls for potential confounding variables, particularly the child's behavioral elicitation of the punishment." (Cohen, Pediatrics, Oct 1996

2. Cognitive leaps

Almost all the studies mix up various approaches in ways that make it difficult, if not impossible, to ascertain the effects of any particular practice. To wit, Lyons, Larzelere, to a degree Baumrind say that the "best studies" actually demonstrate beneficial, not harmful effects of spanking. Then, as evidence, they cite studies like Baumrind's decade-long study of (upper middle class) young families which found that "parents employing a balanced disciplinary style of positive reinforcement and firm control (including spanking) experienced better results with the children than those employing highly authoritarian or highly permissive disciplinary approaches." Yes, of course. I believe everybody agrees that parenting must include both support (nurturance, responsiveness, love) AND control (discipline, demandingness, limits). Larzelere and other spanking proponents then leap to the conclusion that spanking in combination with positive reinforcers results in desirable outcomes. But, what these studies almost never tell us is whether the combination of positive reinforcement and firm control does the job as well or better without the spanking. (Straus conundrum: "Do what you're doing, just leave out the spanking. We go a bit further--set a better example, provide more nurturance, provide more discipline (limits), enforce them firmly, use less punishment, and preferably use no physical at all.)

3.Heavy reliance on self-report--notorious reliability and validity issues

4. Heavy reliance on retrospective data

5. Lack of control or comparison groups

6. No Time 1 data on the outcome variable of interest.

If you don't have a measure of the aggressiveness of the child at Time 1, you won't be able to tell whether child is aggressive at Time 2 because was spanked or whether parents spanked because child was aggressive and difficult. Larzelere criticizes Straus and others on this matter.

7. Overlooking child's age

8. Not taking into account context of the punishment—psychological climate, supportiveness, love

9. Not taking into consideration "cultural context"—the supposedly differing effects when spanking is a "legitimate" practice in the culture.

10. "If several studies find the same relationship between an independent and dependent variable, one can have confidence that such a relationship probably exists, even when the studies are methodologically flawed." (Koski, Marr & Fam Rev 12 (1-2), 1987

"Despite the limitations of each of the studies, the weak point of one study may be dealt with in another. Of course, that other study, in turn will have its own limitations. But when so many different studies, using such a variety of methods, almost always show that corporal punishment is related to violence and other anti-social behavior, it is truly remarkable." (Straus, Pediatrics, Oct 1996, p. 841)

11. Research Design

1. Retrospective—questioned individuals for their retrospective recall of physical punishment experiences during childhood.
   
   
2. Cross-sectional—examined the co-existence of physical punishment and aggression (or whatever) in children.
   
   
3. Prospective/longitudinal
   
   
4. Experimental
   
   

12. "When scientists disagree."

(See Selye, The Stress of Life. pp 277ff; W. B. Cannon. The Way of an Investigator.)

Interpretation of their own data and reviews of others' data are inevitable shaped by the experiential and cultural baggage of the scientist or reviewer. Kuhn spoke about this many years ago. "Succinctly, it is Kuhn's thesis that science does not progress in the logical positivistic manner that we usually talk about. In reality, scientists do not always incorporate new data as data are accumulated; rather, scientists selectively attend to data on the basis of whether or not the data fits into their existing paradigms." (Polite, 1996, p.849; Thomas H. Kuhn. The Structure of Scientific Revolutions. Chicago: University of Chicago Press. 1970. esp pp. 21-44)

At bottom, debate about this or other issues must not be directed by considerations of personal prestige. The question is not "Who is right?" but "What is right?"

R. Pitzer
U of MN Ext
11/97

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