Are Newcomb problems really decisions?

Richard Jeffrey long held that decision theory should be formulated without recourse to explicitly causal notions. Newcomb problems stand out as putative counterexamples to this ‘evidential’ decision theory. Jeffrey initially sought to defuse Newcomb problems via recourse to the doctrine of ratificationism, but later came to see this as problematic. We will see that Jeffrey’s worries about ratificationism were not compelling, but that valid ratificationist arguments implicitly presuppose causal decision theory. In later work, Jeffrey argued that Newcomb problems are not decisions at all because agents who face them possess so much evidence about correlations between their actions and states of the world that they are unable to regard their deliberate choices as causes of outcomes, and so cannot see themselves as making free choices. Jeffrey’s reasoning goes wrong because it fails to recognize that an agent’s beliefs about her immediately available acts are so closely tied to the immediate causes of these actions that she can create evidence that outweighs any antecedent correlations between acts and states. Once we recognize that deliberating agents are free to believe what they want about their own actions, it will be clear that Newcomb problems are indeed counterexamples to evidential decision theory.     

Are the pathogens of out-groups really more dangerous?

We question the plausibility of Fincher & Thornhill's (F&T's) argument that localised pathogen-host coevolution leads to out-groups having pathogens more damaging than those infecting one's own family or religious group.     

Are selective adaptation and contrast effects really distinct?

Although there is evidence that selective adaptation and contrast effects in speech perception are produced by the same mechanisms, Sawusch and Jusczyk (1981) reported a dissociation between the effects and concluded that adaptation and contrast occur at separate processing levels. They found that an ambiguous test stimulus was more likely to be labeled b following adaptation with [pha] and more likely to be labeled p following adaptation with [ba] or [spa] (the latter consisting of [ba] preceded by [s] noise). In the contrast session, where a single context stimulus occurred with a single test item, the [ba] and [pha] contexts had contrastive effects similar to those of the [ba] and [pha] adaptors, but the [spa] context produced an increase in b responses to the test stimulus, an effect opposite to that of the [spa] adaptor. One interpretation of this difference is that the rapid presentation of the [spa] adaptor gave rise to "streaming," whereby the [s] was perceptually segregated from the [ba]. In our experiment, we essentially replicated the results of Sawusch and Jusczyk (1981), using procedures similar to theirs. Next, we increased the interadaptor interval to remove the likelihood of stream segregation and found that the adaptation and contrast effects converged.     

Can semantics be syntactic?

The author defends John R. Searle's Chinese Room argument against a particular objection made by William J. Rapaport called the Korean Room. Foundational issues such as the relationship of strong AI to human mentality and the adequacy of the Turing Test are discussed. Through undertaking a Gedankenexperiment similar to Searle's but which meets new specifications given by Rapaport for an AI system, the author argues that Rapaport's objection to Searle does not stand and that Rapaport's arguments seem convincing only because they assume the foundations of strong AI at the outset.The author wishes to thank Brad Bergeron, David J. Cole, James H. Fetzer, Charles E. Jahren, Michael Losonsky, William J. Rapaport, and Robyn Roslak for reading earlier drafts of this paper and/or their general discussions on cognitive science and AI. An earlier version of this paper was given at the Student Conference of the Minnesota Philosophical Society, Bethel College, 1988.     

Are rules and modules really necessary for explaining language?

Over the past few years Steven Pinker has argued that although some aspects of language may be more associational, and therefore properly modeled in connectionist networks, for the most part human language is still best characterized as a modularized set of rulesymbol systems. In support of his claim, Pinker garners a broad array of clinical, experimental, and observational data from neurology, psychology, and linguistics. Those data, unfortunately, are not compelling because they do not support his position uniquely. In this paper, I show how each of his arguments is compatible with alternative interpretations. I argue, moreover, that in focusing on certain details of connectionist models Pinker and his colleagues actually overlooked both the most serious deficiencies of the connectionist approach and its most significant theoretical contribution. I conclude by sketching briefly some emerging alternatives to connectionism which avoid those deficiencies while retaining its strengths over the rule-symbol systems of linguistic theory.This research was funded in part by University of Idaho Seed Grant 681-Y304.     

Are perceptuo-motor decisions really more optimal than cognitive decisions?

Human high-level cognitive decisions appear sub-optimal (Kahneman and Slovic, 1982, Kahneman and Tversky, 1979). Paradoxically, perceptuo-motor decisions appear optimal, or nearly optimal (Trommershäuser, Maloney, & Landy, 2008). Here, we highlight limitations to the comparison of performance between and within domains. These limitations are illustrated by means of two perceptuo-motor decision-making experiments. The results indicate that participants did not optimize fundamental performance-related factors (precision and time usage), even though standard analyses may have classed participants as ‘optimal’. Moreover, simulations and comparisons across our studies demonstrate that optimality depends on task difficulty. Thus, it seems that a standard model of perceptuo-motor decision-making fails to provide an absolute standard of performance. Importantly, this appears to be a limitation of optimal models of human behaviour in general. This, in conjunction with non-trivial evaluative- and methodological differences, suggests that verdicts favouring perceptuo-motor, or perceptual, systems over higher-level cognitive systems in terms of level of performance are premature.     

Are skeptical theists really skeptics? Sometimes yes and sometimes no

Skeptical theism is the view that God exists but, given our cognitive limitations, the fact that we cannot see a compensating good for some instance of evil is not a reason to think that there is no such good. Hence, we are not justified in concluding that any actual instance of evil is gratuitous, thus undercutting the evidential argument from evil for atheism. This paper focuses on the epistemic role of context and contrast classes to advance the debate over skeptical theism in two ways. First, considerations of context and contrast can be invoked to offer a novel defense of skeptical theism. Second, considerations of context and contrast can be invoked to undermine the two most serious objections to skeptical theism: the global skepticism objection and the moral objection. The gist of the paper is to defend a connection between context and contrast-driven views in epistemology with skeptical views in philosophy of religion.     

Mirror reading in right and left handers: Are sinistrals really superior?

While left handers, where they do in fact appear to differ from right handers in cognitive function, have generally been found to be slightly inferior on verbal tasks, there are some reports of a sinistral superiority for nonverbal or spatial abilities. Tankle and Heilman (Brain and Language, 1982, 17, 124-132) report a sinistral superiority in (obligatory) reading of left-right mirror-reversed text. However, in an investigation which included various other forms of geometrical transformation of the written word, we find that strong familial sinistrals are either not different from or even slightly inferior to dextrals in reading most transformations, including left-right mirror reversals.     

Sex differences among partner preferences: Are the sexes really very similar?

The question as to what type of individual we prefer in a “romantic” partner has stimulated a long history of research, with much of the present debate centering around the issue of the sex differences in partner preferences. In the studies described in this paper, two groups of participants completed a variety of different questionnaire schedules indicating their preferences for a partner. In study 1, 216 single students demonstrated a prevailing desire for a kind, considerate, and honest partner who displayed a keen sense of humor. Consistent with the hypothesis, there were no clear sex differences evident in these results. In study 2, 76 dating agency members completed a similar schedule examining partner preferences. Here again, preferences were similar across the sexes, although men preferred the submissive and introverted partner and stressed the importance of physical appearance in a mate. The general discussion considers the implications of these findings in the light of previous research on partner preferences.