Progress and Degeneration in the 'IQ Debate' (I)
Urbach (Peter)
Source: British Journal for the Philosophy of Science , Vol. 25, No. 2 (Jun., 1974), pp. 99-135
Paper - Abstract

Paper StatisticsBooks / Papers Citing this PaperColour-ConventionsDisclaimer


  1. The Hereditarian and Environmentalist Research Programmes.
    1. The Hard Cores of the Two Programmes.
    2. The Positive Heuristics of the Two Programmes.
    3. Should Scientists Believe the Hard Cores of Their Programmes?
    4. The Theory of General Intelligence versus the Faculty Theory.
  2. The Progress of the Hereditarian Programme.
    1. The Inheritance of Intelligence.
    2. Intelligence and Social Class.
      1. Filial Regression to the Mean and Social Mobility.
      2. Dysgenic Effects.
    3. The Distribution of Intelligence.
    4. Racial Differences in Intelligence.
    5. Conclusion.
  3. The Degeneration of the Environmentalist Programme.
    1. Ad Hoc Explanations of IQ Differences in Terms of Socio-Economic and Cultural Factors.
    2. Ad Hoc Explanations of IQ Differences in Terms of Personality Factors.
      1. Motivation, Internal Control, Self-Esteem and Father-Absence.
      2. The Sensory Deprivation Theory.
      3. The Racial Stress Theory.
    3. Tests of Environmentalist Theories in Compensatory Education Schemes.
    4. The Inheritance of the Environment.
    5. Conclusion

  1. In the question of intelligence, all roads lead back to the work of Francis Galton in the late nineteenth century. He was the first to formulate a theory of 'general intelligence'; he pioneered the construction of mental tests; and he was the inventor of experimental methods for investigating the inheritance of mental abilities.
  2. The controversy between those who hold that individual and group differences in intelligence test scores are primarily due to inherited differences and those who hold they are primarily the products of environmental differences is one of the oldest and most acrimonious in social science. The controversy has been almost universally marred by a lack of clearly defined standards by which to assess the rival theories. Whenever such standards have been invoked, they have been either utopian or unsatisfactory. I intend to describe and appraise the rival views of intelligence in terms of Imre Lakatos's methodology of scientific research programmes and thereby to evaluate the two competing programmes in the light of their objective merits. This will also detach the debate from the political positions with which they are falsely associated in the public mind.
  3. My thesis is that the hereditarian-environmentalist rivalry has existed not between two competing theories but between two competing research programmes. For there have been a series of falsifiable and, indeed, falsified hereditarian and environmentalist theories, each term in each of the two series dealing with some of the refutations (or anomalies) faced by its predecessor. Each of the two series can be characterised by a set of assumptions ('hard cores') common to all the terms. Moreover, each of the series is associated with certain 'heuristic' machinery guiding the construction of successive hypotheses in the series. Thus both the hereditarian and environmentalist approaches possess all the features identified by Lakatos in major physical scientific research programmes.
  4. In section 1 I shall describe the rival hereditarian and environmentalist research programmes. In sections 2 and 3 I shall appraise the development of the two programmes.
  5. As Lakatos has shown – referring to the conventionalist arguments of Le Roy and Milhaud – it is relatively easy for any programme to deal with (that is, make its theories consistent with) any given anomalies. In appraising the programmes, the question is whether they do this in a progressive or in a degenerating manner. The shift within a research programme from one theory to another is progressive if the new theory not only deals with its predecessor's anomalies but also makes extra predictions, some of which are tested and confirmed. On the other hand, if the new theory does nothing more than accommodate the anomalies, the shift is ad hoc and the programme degenerating.
  6. The question we must ask about the hereditarian and environmentalist programmes is not whether they have been proved from the facts (no programme could be), nor whether they are refuted (even the latest versions of both programmes are refuted). On Lakatos's criterion, the fact that a programme is refuted does not, by itself, render it unscientific or unacceptable. The question is whether either programme has successfully 'stuck its neck out' by predicting experimental results which had not been known in advance or whether it simply tinkers with its assumptions in such a way as to accommodate the already observed facts without successfully anticipating further, yet unobserved, novel facts, in the general spirit of the heuristic of the research programme.


See "Urbach (Peter) - Progress and Degeneration in the 'IQ Debate' (II)" for Part II (Section 3).

Text Colour Conventions (see disclaimer)

  1. Blue: Text by me; © Theo Todman, 2021
  2. Mauve: Text by correspondent(s) or other author(s); © the author(s)

© Theo Todman, June 2007 - Jan 2021. Please address any comments on this page to File output:
Website Maintenance Dashboard
Return to Top of this Page Return to Theo Todman's Philosophy Page Return to Theo Todman's Home Page