We investigated the understanding of causal systems categories—categories defined by common causal structure rather than by common domain content—among college students. We asked students who were either novices or experts in the physical sciences to sort descriptions of real-world phenomena that varied in their causal structure (e.g., negative feedback vs. causal chain) and in their content domain (e.g., economics vs. biology). Our hypothesis was that there would be a shift from domain-based sorting to causal sorting with increasing expertise in the (...) relevant domains. This prediction was borne out: The novice groups sorted primarily by domain and the expert group sorted by causal category. These results suggest that science training facilitates insight about causal structures. (shrink)

Reprinted, with modification, from Wilson and Keil 1998.

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine the existence of problem categories as a basis for representation; differences in the categories used by experts and novices; differences in the knowledge associated with the categories; and features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, (...) and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features. (shrink)

The current experiments examine mental health clinicians’ beliefs about biological, psychological, and environmental bases of the DSM‐IV‐TR mental disorders and the consequences of those causal beliefs for judging treatment effectiveness. Study 1 found a large negative correlation between clinicians’ beliefs about biological bases and environmental/psychological bases, suggesting that clinicians conceptualize mental disorders along a single continuum spanning from highly biological disorders (e.g., autistic disorder) to highly nonbiological disorders (e.g., adjustment disorders). Study 2 replicated this finding by having clinicians list what (...) they thought were the specific causes of nine familiar mental disorders and rate their bio–psycho–environmental bases. Study 3 further found that clinicians believe medication to be more effective for biologically based mental disorders and psychotherapy to be more effective for psychosocially based mental disorders. These results demonstrate that even expert mental health clinicians make strong distinctions between psychological and biological phenomena. (shrink)

In a recent contribution, Ereshefsky (2007a) maintained the following points against Nixon and Carpenter (2000), Keller et al. (2003), and Rieppel (2005a, 2006a,b): (1) that species and taxa are individuals, not natural kinds; (2) that “origin essentialism” conflates qualitative essentialism with genealogical connectedness; and (3) that rigid designation theory applies to taxon names. Here I argue that: (1) the conception of species as individuals or natural kinds is not mutually exclusive but rather context sensitive; species are best seen as spatio-temporally (...) located processual systems that instantiate an HPC natural kind; (2) “origin essentialism” is problematic because of the fuzzy boundaries of species and taxa, yet required if rigid designation theory is to apply to taxon names; and (3) the theories of direct reference and rigid designation do not apply to taxon names. (shrink)