Meadow's law
Encyclopedia
Meadow's Law was a precept much in use until recently in the field of child protection, specifically by those investigating cases of multiple cot or crib death — SIDS
— within a single family.
The name is derived from the controversial British
paediatrician, Roy Meadow
, who until 2003 was seen by many as "Britain's most eminent paediatrician"
and leading expert on child abuse. Meadow's reputation went into decline with a series of legal reverses for his theories, and the damage was confirmed in July 2005 when he was struck off the medical register by the General Medical Council
for tendering misleading evidence. Meadow's license was reinstated in February 2006 by a London court.
Meadow attributes many unexplained infant deaths to the disorder or condition in mothers called Munchausen Syndrome by Proxy. According to this diagnosis some parents, especially mothers, harm or even kill their children as a means of calling attention to themselves. Its existence has been confirmed by cases where parents have been caught on video surveillance actively harming their children, but its frequency is subject to debate as Meadow claimed to have destroyed the original data which he used to substantiate the law.
As a result of the 1993 trial of Beverley Allitt, a paediatric
nurse convicted of killing four children under her care and injuring five others, Meadow's ideas gained ascendancy in British child protection circles, and mothers were convicted of murder on the basis of his expert testimony. Thousands of children were removed from their parents and taken into care or fostered out because they were deemed to be 'at risk'. From 2003, however, the tide of opinion turned: a number of high-profile acquittals cast doubt on the validity both of Munchausen's and 'Meadow's Law'. Several convictions were reversed, and many more came under review.
case, Professor Ray Hill endorses a claim that Meadow did not originate
the rule:
The precept was published in the United States
by DiMaio and DiMaio in 1989, without mention of Meadow. In ABC of Child Abuse, first published in the same year, Meadow wrote his formulation:
The formula is “clearly fallacious” according to Bob Carpenter
, Professor of Medical Statistics at the London School of Hygiene and Tropical Medicine, and expert witness in some of the trials where infant cot deaths were prosecuted as homicides.
, particularly relating to probability
, likelihood
, and statistical independence
.
At the trial in 1999 of solicitor Sally Clark
, accused of murdering her two sons, Meadow testified that the odds against two such deaths happening naturally was 73,000,000:1, a figure which he obtained by squaring the observed ratio of births to cot-deaths in affluent non-smoking families (approximately 8,500:1).
This caused an uproar amongst professional statistician
s, whose criticisms were twofold:
in which the probability of "cause given effect" (i.e. the true likelihood of a suspect's innocence) is confused with that of "effect given cause" (the likelihood that innocence will result in the observed double-cot-death). In reality, these quantities can only be equated when the likelihood of the alternate hypothesis, in this case murder, is close to certainty. Since murder (and especially double murder) is itself a rare event, the probability of Clark's innocence was certainly far greater than Meadow's figure suggested.
events, governed by a probability common to the entire affluent-non-smoking population. No account had been taken of conditions specific to individual families (such as a hypothesised "cot death gene
") which might make some more vulnerable than others. The occurrence of one cot-death makes it likely that such conditions exist, and the probability of subsequent deaths is therefore greater than the group average (estimates are mostly in the region of 1:100).
Combining these corrections with estimates of successive murder
probabilities by affluent non-smokers, Mathematics Professor Ray Hill found that the probability of Clark's guilt could be as low as 10% (based solely on the fact of two unexplained child deaths, and before any other evidence was considered). In any case, a legal verdict
is not to be rendered on the basis of statistics; Hill wrote, "guilt
must be proved on the basis of forensic and other evidence and not on the basis of these statistics alone. My own personal view that she is innocent is based on my subjective assessment of all the aspects"
Sudden infant death syndrome
Sudden infant death syndrome is marked by the sudden death of an infant that is unexpected by medical history, and remains unexplained after a thorough forensic autopsy and a detailed death scene investigation. An infant is at the highest risk for SIDS during sleep, which is why it is sometimes...
— within a single family.
History
The "law" has it that because such deaths are a rare phenomenon and difficult to explain by natural causes, we might say that "One is a tragedy, two is suspicious and three is murder unless there is proof to the contrary."The name is derived from the controversial British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
paediatrician, Roy Meadow
Roy Meadow
Sir Samuel Roy Meadow is a British paediatrician and professor, who rose to initial fame for his 1977 academic paper on the now controversial Munchausen Syndrome by Proxy and his crusade against parents who, he believes, wilfully harm or kill their children. He was knighted for these works...
, who until 2003 was seen by many as "Britain's most eminent paediatrician"
and leading expert on child abuse. Meadow's reputation went into decline with a series of legal reverses for his theories, and the damage was confirmed in July 2005 when he was struck off the medical register by the General Medical Council
General Medical Council
The General Medical Council registers and regulates doctors practising in the United Kingdom. It has the power to revoke or restrict a doctor's registration if it deems them unfit to practise...
for tendering misleading evidence. Meadow's license was reinstated in February 2006 by a London court.
Meadow attributes many unexplained infant deaths to the disorder or condition in mothers called Munchausen Syndrome by Proxy. According to this diagnosis some parents, especially mothers, harm or even kill their children as a means of calling attention to themselves. Its existence has been confirmed by cases where parents have been caught on video surveillance actively harming their children, but its frequency is subject to debate as Meadow claimed to have destroyed the original data which he used to substantiate the law.
As a result of the 1993 trial of Beverley Allitt, a paediatric
Pediatrics
Pediatrics or paediatrics is the branch of medicine that deals with the medical care of infants, children, and adolescents. A medical practitioner who specializes in this area is known as a pediatrician or paediatrician...
nurse convicted of killing four children under her care and injuring five others, Meadow's ideas gained ascendancy in British child protection circles, and mothers were convicted of murder on the basis of his expert testimony. Thousands of children were removed from their parents and taken into care or fostered out because they were deemed to be 'at risk'. From 2003, however, the tide of opinion turned: a number of high-profile acquittals cast doubt on the validity both of Munchausen's and 'Meadow's Law'. Several convictions were reversed, and many more came under review.
Attribution to the Di Maios
In a note to his mathematical analysis of the Sally ClarkSally Clark
Sally Clark was a British solicitor who became the victim of an infamous miscarriage of justice when she was wrongly convicted of the murder of two of her sons in 1999...
case, Professor Ray Hill endorses a claim that Meadow did not originate
Stigler's law of eponymy
Stigler's law of eponymy is a process proposed by University of Chicago statistics professor Stephen Stigler in his 1980 publication "Stigler’s law of eponymy". In its simplest and strongest form it says: "No scientific discovery is named after its original discoverer." Stigler named the...
the rule:
The precept was published in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
by DiMaio and DiMaio in 1989, without mention of Meadow. In ABC of Child Abuse, first published in the same year, Meadow wrote his formulation:
The formula is “clearly fallacious” according to Bob Carpenter
Bob Carpenter
Robert E. Carpenter, Jr. is a former professional ice hockey center who played in the National Hockey League for 18 seasons from 1981–82 until 1998–99. In his NHL career that spanned 18 years, Carpenter played 1,178 games, scoring 320 goals and 408 assists for 728 points. He has the distinction of...
, Professor of Medical Statistics at the London School of Hygiene and Tropical Medicine, and expert witness in some of the trials where infant cot deaths were prosecuted as homicides.
Criticisms of Meadow's law
Critics of Meadow's law state that it is based on a fundamental misunderstanding of statisticsStatistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
, particularly relating to probability
Probability
Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
, likelihood
Likelihood function
In statistics, a likelihood function is a function of the parameters of a statistical model, defined as follows: the likelihood of a set of parameter values given some observed outcomes is equal to the probability of those observed outcomes given those parameter values...
, and statistical independence
Statistical independence
In probability theory, to say that two events are independent intuitively means that the occurrence of one event makes it neither more nor less probable that the other occurs...
.
At the trial in 1999 of solicitor Sally Clark
Sally Clark
Sally Clark was a British solicitor who became the victim of an infamous miscarriage of justice when she was wrongly convicted of the murder of two of her sons in 1999...
, accused of murdering her two sons, Meadow testified that the odds against two such deaths happening naturally was 73,000,000:1, a figure which he obtained by squaring the observed ratio of births to cot-deaths in affluent non-smoking families (approximately 8,500:1).
This caused an uproar amongst professional statistician
Statistician
A statistician is someone who works with theoretical or applied statistics. The profession exists in both the private and public sectors. The core of that work is to measure, interpret, and describe the world and human activity patterns within it...
s, whose criticisms were twofold:
The prosecutor's fallacy
Firstly, Meadow was accused of espousing the so-called prosecutor's fallacyProsecutor's fallacy
The prosecutor's fallacy is a fallacy of statistical reasoning made in law where the context in which the accused has been brought to court is falsely assumed to be irrelevant to judging how confident a jury can be in evidence against them with a statistical measure of doubt...
in which the probability of "cause given effect" (i.e. the true likelihood of a suspect's innocence) is confused with that of "effect given cause" (the likelihood that innocence will result in the observed double-cot-death). In reality, these quantities can only be equated when the likelihood of the alternate hypothesis, in this case murder, is close to certainty. Since murder (and especially double murder) is itself a rare event, the probability of Clark's innocence was certainly far greater than Meadow's figure suggested.
Statistical independence
The second criticism was that Meadow's calculation had assumed that cot deaths within a single family were statistically independentStatistical independence
In probability theory, to say that two events are independent intuitively means that the occurrence of one event makes it neither more nor less probable that the other occurs...
events, governed by a probability common to the entire affluent-non-smoking population. No account had been taken of conditions specific to individual families (such as a hypothesised "cot death gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
") which might make some more vulnerable than others. The occurrence of one cot-death makes it likely that such conditions exist, and the probability of subsequent deaths is therefore greater than the group average (estimates are mostly in the region of 1:100).
Combining these corrections with estimates of successive murder
Double murder
Double murder is a term used to describe the act of unlawfully killing two people. This is commonly punished by back-to-back life sentences. It is possible but rare for a double-murder charge to be enforced in cases of homicide in which a pregnant woman is murdered, thereby killing her unborn...
probabilities by affluent non-smokers, Mathematics Professor Ray Hill found that the probability of Clark's guilt could be as low as 10% (based solely on the fact of two unexplained child deaths, and before any other evidence was considered). In any case, a legal verdict
Verdict
In law, a verdict is the formal finding of fact made by a jury on matters or questions submitted to the jury by a judge. The term, from the Latin veredictum, literally means "to say the truth" and is derived from Middle English verdit, from Anglo-Norman: a compound of ver and dit In law, a verdict...
is not to be rendered on the basis of statistics; Hill wrote, "guilt
Guilt (law)
In criminal law, guilt is entirely externally defined by the state, or more generally a “court of law.” Being “guilty” of a criminal offense means that one has committed a violation of criminal law, or performed all the elements of the offense set out by a criminal statute...
must be proved on the basis of forensic and other evidence and not on the basis of these statistics alone. My own personal view that she is innocent is based on my subjective assessment of all the aspects"