Commentary: Domestic Violence, Folk Etymologies, & "Rule of Thumb"

Commentary: Domestic Violence, Folk Etymologies, & "Rule of Thumb" 

© (1998) By  Jennifer Freyd and JQ Johnson

Like many folk etymologies, the commonly understood origin of "rule of thumb" seems to have some inaccuracy. The Oxford English Dictionary indicates that the phrase has been used for about 300 years to refer to measurements that are based on experience instead of exact science. However, some people currently believe that the phrase "rule of thumb" originated from English common law, and that the phrase reflects a law which allowed a husband to beat his wife with a whip or stick no bigger in diameter than his thumb.

Others have used this belief as an example of feminist exaggeration. For instance, Christina Hoff Sommers, in her 1994 book Who Stole Feminism: How Women have Betrayed Women wrote on page 203: "Because many feminist activists and researchers have so great a stake in exaggerating the problem and so little compunction in doing so, objective information on battery is very hard to come by. . .The 'rule of thumb' story is an example of revisionist history that feminists happily fell into believing."

Our reading of the literature in this area suggests that the interpretation that there was a legal standard about hitting wives that relates to the size of a "thumb," came not from feminists or grassroots activists but is much older and comes perhaps from a judge from the American South over a century ago. In recent years many people in society, including feminists and non-feminists, the popular press (and not necessarily a feminist popular press), have contributed toward the "story" of the phrase that relates it to English common law.

The reality about the history of this phrase seems to be a fascinating and complex. The best current source of which we are aware is:

Kelly, Henry Ansgar (1994). Rule of Thumb and the Folklaw of the Husband's Stick. Journal of Legal Education 44 (3) [Sep 1, 1994], 341-365.

Kelly's overall position is that the "rule of thumb" is not a principal enshrined in the law, and that this idea that it is enshrined in law derives from a 1977 book by Davidson who claims that a "rule of thumb" is a traditional justification for wife-beating. He goes further to argue that the extent to which wife beating is accepted in the law varies with the source, but that in general wife beating (whether with a thumb-sized cane or anything else) is not traditionally permissible.

On the recent history of the idea of a "rule of thumb," Kelly's argument seems interestingly inconsistent. On the one hand he traces its misuse to Davidson (1977), but on the other hand he notes that Davidson and others cite William Prosser (1971) as a source. He observes as evidence that the error starts with Davidson that what Prosser actually says is "there is probably no truth whatever in the legend that he was permitted to beat her with a stick no thicker than his thumb." Prosser thus acknowledging a tradition that DOES involve a thumb standard, albeit without legal merit.

Kelly notes that the exact phrase "rule of thumb" itself never occurs in legal history, and that the idea of the thumb as a standard appears in "only" a handful of cases.

In America he cites a North Carolina case, State v Rhodes, 1868 61 N.C. 453, as "the only case on record in which a husband was let off because 'His Honor was of opinion that the defendant had a right to whip his wife with a switch no longer than his thumb.'" [Kelly, p. 345]. The State Supreme Court repudiated this argument but dismissed the case on the basis that the husband had not actually harmed the wife substantially. In other words, the rule of thumb was illegal, but wife-beating was legal as long as it didn't inflict much permanent damage.

Kelly also cites Bradley v State, 1824, 1 Miss (1 Walker) 156, in which the justice (Powhattan Ellis) acknowledges the existence of a popular thumb standard but rejects it as justification in the particular case.

In English law, Kelly notes that judge Sir Francis Buller, in 1782 (1781?) gave credence in a legal opinion to a "thumb" standard for permissible wife beating, and that this decision was cause for production of a set of cartoons of the period critical of Buller. 

After reading Kelly, we are left with a somewhat different conclusion than his. He does argue persuasively that the "rule of thumb" has never been a widely accepted legal principal, and that the phrase itself has not had the wife-beating overtones until recently. However, his own research leads us to conclude that there was a popular (though far from universal) perception as early as 1782 that wife beating was acceptable and that a thumb standard for the instrument was appropriate.

On the general issue of the acceptability of domestic violence there seems little doubt that there has been a wide range of acceptance and approbation both in law and in popular culture. And there can also be little doubt that one's interpretation of the past is heavily colored by one's beliefs -- we read the same texts as Kelly and come away with an overall impression quite different from his.

We caution readers to use restraint in judging others harshly for either their use of the phrase "rule of thumb" or for their pain in hearing the phrase used and believing it refers to domestic violence. Keep in mind that folk etymologies are very often incorrect, and deriding people for a false belief in this area serves little purpose. Most importantly, the problem of domestic violence is truly severe, and our energy is best spent on understanding and preventing domestic violence.