5,217 research outputs found
On the functional origins of essentialism
This essay examines the proposal that psychological essentialism results from a history of natural selection acting on human representation and inference systems. It has been argued that the features that distinguish essentialist representational systems are especially well suited for representing natural kinds. If the evolved function of essentialism is to exploit the rich inductive potential of such kinds, then it must be subserved by cognitive mechanisms that carry out at least three distinct functions: identifying these kinds in the environment, constructing essentialized representations of them, and constraining inductive inferences about kinds. Moreover, there are different kinds of kinds, ranging from nonliving substances to biological taxa to within-species kinds such as sex, and the causal processes that render these categories coherent for the purposes of inductive generalization vary. If the evolved function of essentialism is to support inductive generalization under ignorance of true causes, and if kinds of kinds vary in the implicit assumptions that support valid inductive inferences about them, then we expect different, functionally incompatible modes of essentialist thinking for different kinds. In particular, there should be differences in how biological and nonbiological substances, biological taxa, and biological and social role kinds are essentialized. The functional differences between these kinds of essentialism are discussed
Understanding death as the cessation of intentional action: A cross-cultural developmental study
Determining whether or not an entity is capable of acting intentionally is a fundamental cognitive skill that emerges in the first year of infancy, and the inability to act is a key aspect distinguishing dead from living things. Though young childrenÂ’s understanding of death is generally thought to be poor, an understanding of death as the permanent cessation of agency might develop early in childhood. This study tested the cessation-of-agency hypothesis cross-culturally, by examining the differences between childrenÂ’s judgments about sleeping and dead animals. The results showed that children understand that death entails the permanent cessation of the ability to act by age 4 in two different cultures. This is consistent with a view that those distinctions that are most crucial for adaptive decision-making are the ones that develop earliest
An Evaluation of Reserve Component Leaders\u27 Attitudes and Motivation as They Relate to Situational Leadership Theory in a Peacekeeping Operational Environment
Program. This study investigated the relationships between Reservist leaders\u27 attitudes and Hersey and Blanchard\u27s Situational Leadership Theory (SLT), and Thomas\u27s Integrative Model of Intrinsic Motivation during a 2004 Sinai, Egypt, peacekeeping mission.
Methodology. This descriptive study provided quantitative and qualitative results. Three instruments were used with a convenience sample of leaders within one forward-deployed National Guard infantry battalion. The LEADSelf instrument determined the SLT style of unit officers and non-commissioned officers. The Thomas Empowerment Survey profiled participants\u27 intrinsic motivation. A researcher-developed survey determined preferences for intrinsic versus extrinsic motivator factors.
The study centered on the following issues: (1) Are the participants satisfied with their involvement in the National Guard and the peacekeeping mission? (2) Is there a significant relationship between intrinsic levels of motivation as measured by Thomas\u27s model and volunteerism (or hypothetical volunteerism) in the participants? (3) Are the participants motivated by intrinsic or extrinsic factors to take part in the study peacekeeping operation?
Results. Seventy-four percent of the respondents to the SLT survey reported a high task and high relationship S2 Selling leadership style.
Less than 10% of the respondents felt high levels of intrinsic motivation in the areas of Choice, Competence, and Progress as measured by the Thomas scale. Similarly, 22% of the respondents reported a high sense of Meaningfulness.
Regarding the research hypotheses, no significant relationships could be established between volunteerism/hypothetical volunteerism and Thomas\u27s intrinsic factors using chi-square statistics. However, there was qualitative support for this relationship.
The ultimate desire of the study was to see whether intrinsic or extrinsic factors held greater sway on these Reserve soldiers in a peacekeeping environment. What motivated them? Soldiers preferred intrinsic factors over extrinsic factors. They also reported displeasure when these intrinsic factors were absent.
Conclusions. (1) There was no quantitative support for the research questions studying relationships between volunteerism/hypothetical volunteerism and Thomas\u27s intrinsic motivation factors. (2) However, qualitative support suggested that soldiers are intrinsically motivated to participate in peacekeeping operations and the National Guard in general. (3) Respondents indicated they could be both dissatisfied and satisfied in aspects of their military career and the Sinai peacekeeping mission
A Quantitative Analysis of Calcareous Nannofossils Across a Late Oligocene Paleolatitude Transect of the North Atlantic Ocean
Samples from ODP Sites 926, 628, 563, U1406, 647, and 918, were analyzed quantitatively across a paleolatitude transect of the North Atlantic Ocean to determine the paleolatitudinal distribution of calcareous nannofossils in the Late Oligocene and the effects of that distribution on biostratigraphic resolution. Detrended Correspondence Analysis (DCA), a Temperature index (TI), and the Shannon Diversity Index (H), were used to examine the paleoenvironmental gradients which exerted the most control over the distribution of species and their abundances. The temperature index correlates significantly to the first axis of the DCA, suggesting that thermal controls were the most important factor in the distribution of Late Oligocene nannofossils in the North Atlantic. Shannon Diversity and the percent abundance of the taxon Reticulofenestra minuta correlates significantly to DCA 2, suggesting that surface water mass fertility was an important secondary controlling factor during the Late Oligocene. A biochronological analysis utilizing Unitary Associations (UA) divided the assemblage into 6 UAs, correlating with the biostratigraphic scheme of Agnini et al. (2014). UA 3 and UA 4, defined by the base of Sphenolithus calyculus, was not used in the Agnini et al. (2014) biozones, and offers an additional bioevent for the Upper Oligocene. The absence of UA 5 at Hole 926B reveals a disconformity that was not identified previously. The zonation scheme of Bergen et al. (2017) which utilizes S. calyculus, and Agnini et al. (2014) cannot be accurately applied to the North Atlantic Ocean north of 53° latitude. The best biostratigraphic resolution in the Late Oligocene North Atlantic is restricted to the upper mid latitudes Sites 628, 563, and U1406. These latitudes, from 27-40°, represent the warm gyre center and the temperate gyre perimeter.
Advisor: David K. Watkin
On Counterexample Guided Quantifier Instantiation for Synthesis in CVC4
We introduce the first program synthesis engine implemented inside an SMT
solver. We present an approach that extracts solution functions from
unsatisfiability proofs of the negated form of synthesis conjectures. We also
discuss novel counterexample-guided techniques for quantifier instantiation
that we use to make finding such proofs practically feasible. A particularly
important class of specifications are single-invocation properties, for which
we present a dedicated algorithm. To support syntax restrictions on generated
solutions, our approach can transform a solution found without restrictions
into the desired syntactic form. As an alternative, we show how to use
evaluation function axioms to embed syntactic restrictions into constraints
over algebraic datatypes, and then use an algebraic datatype decision procedure
to drive synthesis. Our experimental evaluation on syntax-guided synthesis
benchmarks shows that our implementation in the CVC4 SMT solver is competitive
with state-of-the-art tools for synthesis
Combining SAT Methods with Non-Clausal Decision Heuristics
AbstractA decision procedure for arbitrary first-order formulas can be viewed as combining a propositional search with a decision procedure for conjunctions of first-order literals, so Boolean SAT methods can be used for the propositional search in order to improve the performance of the overall decision procedure. We show how to combine some Boolean SAT methods with non-clausal heuristics developed for first-order decision procedures. The combination of methods leads to a smaller number of decisions than either method alone
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