The evolution of the behavior systems framework and its connection to interbehavioral psychology.

The present article traces the development of Timberlake's behavior systems framework while noting connections between it and Kantor's interbehavioral psychology. Congruent with Timberlake's behavior systems approach, interbehaviorists assert that (a) behavior is best understood as part of a complex causal system instead of a simple linear model, (b) the study of learning and behavior analysis should consist of the study of multiple responses and the systematic observation of response forms, (c) learning involves the reorganization of a behavior system, (d) behavioral analyses should be more ecological in orientation, and (e) psychology would benefit from a set of methodologies and apparatuses broader than those normally used to study operant and Pavlovian conditioning. These connections may derive from two broad themes shared by the behavior systems framework and interbehavioral psychology: an appreciation for a systems view of behavior and the importance of ethological considerations.

Task-specific modulation of adult humans' tool preferences: number of choices and size of the problem.

In two experiments, we examined the effect of modifications to the features of a stick-and-tube problem on the stick lengths that adult humans used to solve the problem. In Experiment 1, we examined whether people's tool preferences for retrieving an out-of-reach object in a tube might more closely resemble those reported with laboratory crows if people could modify a single stick to an ideal length to solve the problem. Contrary to when adult humans have selected a tool from a set of ten sticks, asking people to modify a single stick to retrieve an object did not generally result in a stick whose length was related to the object's distance.

More but not less uncertainty makes adult humans' tool selections more similar to those reported with crows.

In this study, we examined whether adult humans' tool selections in a stick-and-tube problem might resemble previously published results of crows' selections if people had more experience solving the problem or were presented with a more ambiguous problem. In Experiments 1a and 1b, when given multiple opportunities to select a stick from a set of 10 to retrieve a candy located either 8 or 16 cm from the opening of a tube, the participants always selected a stick that was long enough to retrieve the candy; however, they did not generally select either the stick whose length matched the object's distance or the longest stick in the set-two outcomes reported in studies with crows. In Experiment 2, participants who were allowed only a brief period of time to study the problem selected a longer stick than did participants allowed unlimited time to do the same.

How do adult humans compare with New Caledonian crows in tool selectivity?

We examined humans' tool selections on stick-and-tube tasks similar to those used to study crows' and other avian species' physical cognition. In Experiment 1, the participants selected a stick from a set of 10 to retrieve a candy placed in a horizontal tube. Although the stick that was selected depended on the distance to the candy, the participants generally did not select a stick whose length was the same as the candy's distance from the open end of the tube nor did they select the longest stick in the set-two strategies that have been reported in crows.

Humans' folk physics is not enough to explain variations in their tool-using behavior.

Two experiments examined adult humans' folk physics (i.e., their naturally occurring and spontaneous understanding of the physical world) using variations of trap-table problems used to study chimpanzees' folk physics.

A behavior systems view of the organization of multiple responses during a partially or continuously reinforced interfood clock.

We examined how a 50% Pavlovian partial reinforcement (PRF) schedule, versus a 100% continuous reinforcement (CRF) schedule, altered the asymptotic amount and distribution of focal and general search behavior in rats during 48-sec trials with and without a four-segment interfood clock (S1-S2-S3-S4-US). Under CRF, but not PRF, average asymptotic focal search (nosing in the feeder) increased across the last two clock segments (S3 and S4), and more for the clock group than the no-clock group. Locomotor general search peaked in the second clock segment (S2) for the CRF-clock and CRF-no-clock groups and in S3 for the PRF-clock groups.

Methodological-conceptual problems in the study of chimpanzees' folk physics: how studies with adult humans can help.

In three experiments, we examined humans' folk physics (i.e., a naturally occurring and spontaneous understanding of the physical world), using variations of problems used to study chimpanzees' folk physics.