The estimation of ultrametric and path length trees from rectangular proximity data

A least-squares algorithm for fitting ultrametric and path length or additive trees to two-way, two-mode proximity data is presented. The algorithm utilizes a penalty function to enforce the ultrametric inequality generalized for asymmetric, and generally rectangular (rather than square) proximity matrices in estimating an ultrametric tree. This stage is used in an alternating least-squares fashion with closed-form formulas for estimating path length constants for deriving path length trees. The algorithm is evaluated via two Monte Carlo studies. Examples of fitting ultrametric and path length trees are presented.G. De Soete is Aspirant of the Belgian Nationaal Fonds voor Wetenschappelijk Onderzoek at the University of Ghent, Belgium. W. S. DeSarbo and J. D. Carroll are Members of Technical Staff at AT&T Bell Laboratories, Murray Hill, N.J. G. W. Furnas is Member of Technical Staff at Bell Communications Research, Murray Hill, N.J.     

Academic and nonacademic community psychologists: An analysis of divergence in settings,roles, and values

Differences between academic and nonacademic psychologists may be viewed as immutable, worthy of encouragement, or as a situation which the latter group must remedy by becoming “more scientific.” We contend that for community psychology, which perceives theory, application, and action as valid aspects of its broad paradigm, it would be most adaptive toexplicitly address the challenge of managing a balance between diversity and cohesion. There are signs that the present leadership of Division 27 recognizes aspects of this problem and is reconsidering the role and purpose of the Division as an organizing framework for the discipline (Trickett, Note 3). It is our view that engendering a commitment from various subgroups within the membership to addressing the disparities revealed by our respondents is required for resolving what we see as major obstacles to future development of the discipline. The conceptual and empirical approach presented in this study can be an important tool in forging constructive solutions to the challenges we have presented.     

Toward a model for spirituality and alcoholism

Spirituality is a significant factor in recovery from alcoholism, whatever definition of this condition one may use. One aspect of alcohol abuse is its apparent relationship to the balance between brain hemispheres. Excessive use of alcohol anesthetizes the object-based, language-oriented functions of the left hemisphere, associated with an action mode of consciousness. This allows greater engagement of the right-hemisphere receptive mode, which is also associated with religious experience. A model of spirituality based on achieving a balance between hemisphere functions and modes of consciousness could provide a non-chemical alternative to excessive use of alcohol.     

In and behind a Lenneberg paradigm

Lenneberg suggested that a chimpanzee's linguistic ability could be tested by presenting sentences containing two prepositional phrases joined by a conjunction. This would involve joining two semantic propositions, and thus represents a more complex test of chimpanzee syntactic competence than previously attempted. Jane, a five year-old language trained chimpanzee, was tested on her ability to both produce and comprehend sentences involving a preposition (in or behind) and a conjunction (and). The results from production and comprehension were substantially the same. Jane showed the ability to appropriately deploy and, behind and in, but displayed very little flexibility in their use. It is suggested that a chimpanzee may be able to learn some rules of syntax but is not able to be creative with that syntax.     

Pavlov’s position on the effects of decortication on conditional reflexes

This paper examined D. Joravsky’s (1989) hypothesis that I.P. Pavlov dogmatically refused to acknowledge that classical conditioning can be mediated by subcortical regions of the large cerebral hemispheres. Decortication literature from 1901 to 1936 was reviewed. The early studies available to Pavlov, who died in 1936, showed that decortication does not allow the establishment of new or retaining of old conditional reflexes (CRs). G.P. Zelenyi’s later experiments(1930) suggested that the establishment of primitive CRs in decorticated dogs was possible. Pavlov never denied this possibility but cautioned that Zelenyi’s experiments could have been methodologically flawed. Although Joravsky’s original hypothesis on Pavlov’s position on the relation between decortication and the establishment of CRs is by and large accepted, it must be stressed that Pavlov’s theory of higher nervous activity was primarily concerned with the function of the brain in the higher organism’s struggle for existence. Within this context the cortical, rather than subcortical, processes play the decisive role in the organism’s adaptation to the changing external environment.     

Mothers' Experience of Stress Following the Birth of a First Child: Identification of Stressors and Coping Resources1

The purpose of this study is to identify, through a retrospective methodology, stressor and coping resource variables which are involved in mothers' experience of stress one month after the birth of a first child. The variables were identified on the basis of previous work in this field, and were categorized as stressor or coping resource variables according to the writings of authors in the larger domain of stress and coping. The influence of interactive and additive combinations of stressors and coping resources, as described by Wheaton (1985), were also examined in a multiple regression model. A five-variable model, accounting for 58.74% of the variance of a measure of the experience of stress, was obtained. Discussion focuses around the predictive possibilities of such a model, the impact of coping resources, and on the potential for utilizing this model for describing the process of adaptation following this event over time.