Unlike some psychiatric illnesses, criminal lifestyles are not reproductive dead ends and may represent frequency-dependent adaptations. Sociopaths may gain reproductively from their greater “mating effort” relative to nonsociopaths. This mating-effort construct should be assessed directly in future studies of sociopathy. Collaboration between biologically oriented and environmentally oriented researchers is needed to investigate the biosocial basis of sociopathy.

Understanding the bases of complex behavioral phenotypes, such as sociopathy, is assisted by an evolutionary approach, in addition to other theoretical perspectives. Unraveling genetic and environmental factors underlying variant forms of sociopathy remains a key challenge for behavioral science investigators. Twin research methods (e.g., longitudinal analyses; twins reared apart) offer informative means of assessing novel hypotheses relevant to sociopathic behaviors.

The validity of the classification of “primary sociopaths” as a qualitatively distinct group in the general population is questioned. Cenetic variation in the experience and expression of emotions may play a role in the development of antisocial behavior. However, research clearly documents that socialization environments powerfully modify the expression of genetic biases in a manner that increases or decreases the risk for “sociopathy.”

Mealey's sociobiological model of sociopathy could profit from attachment theory, in particular, the theory and research on the basis of the Adult Attachment Interview (Main & Goldwyn 1985–1993). Findings of an adult attachment study in a forensic psychiatric setting are summarized. Three attachment-oriented strategies for families, schools, and forensic settings are proposed to help reduce or prevent secondary sociopathy and criminal recidivism.

If sociopathy is a biological adaptation, it probably evolved in small social groups in which individuals lacked the social mobility required for a con-man strategy to work. On the other hand, conflicts between groups may have provided a large niche for sociopathy throughout human history.

Problems of definition and identification in the integrated evolutionary model of sociopathy are suggested by Schoenfeld's (1974) criticism of the field of race differences in intelligence. Moral judgments by those labeled primary and secondary sociopaths may offer a way to validate the assumptions of the model.

Psychopathy has as its central traits socialization, sensation seeking, and impulsivity. These are combined in a supertrait: Impulsive Unsocialized Sensation Seeking (ImpUSS). Secondary types are defined by combinations of ImpUSS and neuroticism or sociability. All broad personality traits have both genetic and environmental determination, and therefore different etiologies (primary as genetic, secondary as environmental) for primary and secondary sociopathy are unlikely.

Recent studies lend support to the two-pathway model of the evolution of sociopathy with evidence that: 1) psychopathy (primary sociopathy) is a discrete type and 2) in general, sociopaths have relatively high levels of reproductive success. Hare's Psychopathy Checklist may provide a start for the revision of terminology that will be necessary to distinguish between primary and secondary trajectories.

Given that psychophysical responses are not a function of a single property but vary with a variety of stimulus and context variables, Lockhead has little hope for laws relating behavior to the environment. However, progress can be made with tasks that manipulate multiple sources of information to test formal information-processing models.

In contrast to Lockhead's view it is argued that psychology as a genuine science must not be based on other sciences and that psychological measurements have to be validated inside psychology. It is pointed out that psychological scalings, unaffected by judgment contexts, can be obtained if the experimental setting is compatible with everyday situations.

In his target article Lockhead calls attention to numerous complications that prevent a valid straightforward or Fechnerian interpretation of psychophysical data. Here I describe three additional sources of bias, all involving the influence of stimuli presented before the start of an investigation.

Psychophysical scales can be constructed under suitable restrictions from appropriate data, but they still do not justify privileged internal sensations.

In terms of physics, mass is the fixed attribute of an object while weight varies with the accelerative force. Neither weight nor mass are simple sensory stimuli as both involve the integration of sensory and motor information with higher cognitive processes. Studies of apparent heaviness yield only vague information about sensorimotor mechanisms.

People cannot make independent judgements of stimulus attributes and so “it is necessary to theorize in terms of stimulus structures” (Lockhead 1992, p. 551) rather than in terms of stimulus features. The new commentaries here further this statement and also support the observations in the target article that psychophysical scaling methods allow us to measure (1) how context determines judgments and (2) what people remember about prior stimuli.

Searle (1990) argues that unconscious intrinsic intentional states must be accessible to consciousness because (1) all intrinsic intentional states have aspectual shape, the “ontology” of which cannot be explained in a third-person (e.g., neurophysiological) vocabulary, and (2) ontologically, unconscious mental states are neurophysiological processes. This argument confuses three senses of “ontology,” namely, factuality, individuative properties, and phenomenological presence.

Searle's (1990) argument for the “Connection Principle” seems to rest on a confusion between ontological and epistemological claims. The potential consciousness of a mental state does not yield the same effect as does its actual consciousness, namely, the preservation of aspectual shape. Searle's distinction between the consciousness of an intentional object and that of a mental state, which is meant to counter the objection that deep unconscious rules cease to be deep once they become conscious, fails to do its appointed task.