Human Evolution, Reproduction, and Morality

Transcription

1 Human Evolution, Reproduction, and Morality

2 Human Evolution, Reproduction, and Morality LEWIS PETRINOVICH University of California Riverside, California SPRINGER SCIENCE+BUSINESS MEDIA, LLC

3 Library of Congress Cataloging-in-Publication Data On file ISBN DOI / ISBN (ebook) Springer Science+Business Media New York 1995 Originally published by Plenum Press, New York in 1995 Softcover reprint of the hardcover 1st edition All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

4 Preface My initial interest in the issues considered in this book was triggered by questions regarding animal rights. I took my PhD. in physiological psychology at the University of California at Berkeley and began academic research studying brain function and learning. Specifically, I studied the effects of drugs that stimulate the nervous system on the characteristics of maze and discrimination learning by rats and expanded that research to study the effects of various types of brain lesions on the retention of learned responses. I continued this line of research for a number of years until I realized that the constraints of the laboratory often made it difficult to generalize the principles I had developed beyond the laboratory, and that the specific conditions of the experiments often prevented generalization to the universe of events I intended to understand at the outset of the research program. I decided that it would be useful to study behaviors that organisms are designed by nature to perform and chose the development of language as a likely candidate. Normal human brains do not require specific training to develop a language. It is only necessary for an infant to be exposed to a language community at an appropriate time, and the infant comes to comprehend and express the language of that community without any conscious training on the part of adult models. This state of affairs, it seemed to me, could provide the royal road to an understanding of what brains need to do and how they do it. I read in the psycholinguistic and child development literature to gain some understanding of how human language is used and how it develops. Because it is not possible to manipulate systematically the sensory input received by infants to investigate the operation of the biological and cognitive systems, I cast about for another languagelike system to study. The v

5 vi Preface system that seemed to possess many of the characteristics in which I was interested was that involved in the development of song dialects by birds; specifically the white-crowned sparrows (Zonotrichia Zeucophrys that are located along the west coast of the United States. Young birds develop a distinctive and stable vocal pattern as a result of mere exposure to singing adults. These young birds develop the vocal characteristics of the prevailing "language" environment much in the way that human infants do, and I decided that the song system would be much easier to understand because it consists of only a single two-second-iong song. Because this species of bird does not breed readily in captivity it was necessary to collect young birds in the field before they had experience with adult song in order to study song development in the laboratory. To find nests and remove the nestlings for study, I had to make extensive field observations of breeding populations of white-crowned sparrows. Alas, a true "slippery slope" developed. The more field experience I accumulated, the more questions regarding the functional significance of song dialects came to interest me, and to approach these questions it was necessary to understand the principles of evolutionary biology. These questions led me to conduct field studies of the distribution of song types, the stability of dialect systems through time, and studies of the transmission of song from bird to bird across generations of singers. These concerns led to studies of mating patterns and population structure and to thoughts of how to place these findings in a perspective that included population genetics and sociobiology. While teaching my undergraduate course in comparative psychology, I came to realize that those of us who engage in laboratory and field studies of animals have an extensive set of implicit assumptions that justifies our research. However, we seldom bother to make these assumptions explicit, either to ourselves, to our colleagues, or to the public. This realization was quickened by the virulent and destructive attacks of members of the animal rights movement on the animal research community at our university. I decided that it was incumbent upon me to examine the underlying implicit presuppositions on which much of my academic life's work had been based. I began to read moral philosophy to develop an understanding of what is generally referred to as bioethics. I have now negotiated that slippery slope and arrived at a stopping place. This book is the result of a piece of that extensive journey. I approach the development of a personal ethic from the perspective of a behavioral scientist who has had an active research career in psychology and biology. I hope to develop an understanding of the implicit and unexamined beliefs professional scientists have regarding underlying moral issues because I believe firmly that the unexamined life is not worth

6 Preface vii living, and that one's own most basic beliefs and values should be subjected to critical scrutiny. Nobel laureate George Snell (1988) adopted what he called the principle of self-interest as the starting point in his search for a rational ethic to guide the scientist and the layperson attempting to deal with modem ethical dilemmas. He argued that one can recognize a truly enlightened choice when one comes to understand the dictates of selfinterest. When faced with a choice between alternative courses of action, pure self-interest must be acknowledged in order to develop an acceptable rational ethics. I intend to examine and describe some of the underlying beliefs and intuitions that people have regarding moral and biological issues involved in human life, and to use this descriptive base to develop an ethic based on what I call a rational liberalism. In earlier writings I have devoted considerable attention to an examination of the implicit assumptions involved when scientists measure, experiment, and perform logical and statistical analyses of data (Petrinovich 1979, 1981). I have tried to identify problems that occur when scientists decide to observe certain events in certain ways and then bring the results of these observations to bear on theoretical concerns (Petrinovich 1989, 1990). I began the present inquiry by analyzing the moral positions that behavioral scientists use, or at least should consider, when they decide to experiment using animals as subjects. These analyses led me to the realization that any adequate moral position would have to be broader than those concerning only nonhuman animals. Moral principles should be framed broadly enough to provide guidelines for all issues pertaining to life, whether it be plant, animal, or human. I agree with the moral philosopher Michael Tooley (1983) who argued that it is essential to discuss morality in terms that are broad enough to cover the widest variety of substantive issues under a uniform set of principles. The same principles should apply to issues regarding contraception, abortion, infanticide, death of humans, and keeping, killing, and consuming nonhuman animals. It is not tenable, rationally, to use a number of different moral systems, each specially designed to apply to a specific case. It is important to develop consistent moral principles, especially if they are to justify arguments regarding decisions that influence reproductive practices, the termination of life, and the pursuit of biomedical research. We should examine these moral positions carefully in regard to a broad range of related issues pertaining to life and its quality on earth, and I begin such an examination in this book. This enterprise is not only the pursuit of a personal quest; it can be argued that humanity stands at a crossroads that makes it necessary for such inquiry to be approached in depth. The philosopher and social ethi-

7 viii Preface cist John Harris (1992, p. 2) began his book Wonderwoman and Superman by pointing out that" for the first time we can literally start to shape not only our own destiny in terms of what sort of world we wish to create and inhabit, but in terms of what we ourselves wish to be like. We can now, literally change the nature of human beings." The arguments that I develop attempt to bring to bear the thinking of biologists (both organismic and evolutionary), moral philosophers, cognitive scientists, and social and developmental psychologists. I believe it is essential to consider matters at this multidisciplinary level. I have encountered the argument that, given the immense complexity involved in such things as human morality, it is neither possible nor profitable for any one individual to present a multidisciplinary perspective. This argument might have some merit if the goal is to present a comprehensive philosophical treatise that considers the various extant philosophical positions, arguing the merits and demerits of each, and bringing the available evidence to bear in evaluating the various positions. The force of that argument is diminished if the intent is to provoke a community of scholars (including biological and social scientists, philosophers, and policymakers) to consider these issues with a broad intellectual scope. The specialists can straighten out the problematic details later, philosophers can take delight in pointing out that their favored positions were not discussed, and scientists can bring more and different substantive data to bear. The advantage of having one person make the presentation is that it avoids the unevenness inherent in edited volumes and has the advantage (one hopes) of being argued in a consistent voice. I agree with Tooley (1983, p. 425), who concluded that "there is unfortunately a tradition of splendid isolation that has grown up between philosophy and the sciences. While that endures, there is little hope that these issues can be completely resolved." I hope I have been able to reduce that splendid isolation. I acknowledge the valuable assistance of several colleagues and friends. Taylor Stoehr, Professor of English at the University of Massachusetts at Boston, professional writer, and a friend for 40 years, read the first draft of the manuscript and scolded me into developing a more consistent voice. Dr. A. J. Figueredo, one of my PhD. students and now professional collaborator, read the next two complete drafts and improved the organization, coaxing me to greater clarity. The penultimate draft received a careful critical reading by Joel Feinberg and Bruce Sales. I also received helpful comments on some of the chapters from Marc Bekoff, Paul Bloom, Martin Daly, Joel Feinberg, Grete Haberman, Patricia O'Neill (another of my Ph.D. students who has gone on to bigger and better things). I have profited from the excellent treatment of the principles of moral philosophers by John Fischer and Mark Ravizza (1992), and I am pleased to

8 Preface ix acknowledge my deep indebtedness to both of them for listening to my wonderings and wanderings and guiding me to this writer and to that thought. I recommend their book of critical essays, especially their introductory chapter, which is a concise discussion of some of the relevant basic philosophical principles. I would like to say that all the good stuff was my doing and that any faults that remain are due to the bad advice given by the above individuals. However, that statement would be untrue; so to serve the interest of honesty, I conclude they did good and I tried my best.

9 Contents PART I. BASIC PRINCIPLES 1. The Basic Approach Introduction: The Nature of this Enterprise... 3 Guidelines for Argument Six Standards for Argument Rawls and Methodology Strategy of the Present Scheme of Argument Some Additional Considerations Plan of Attack The Naturalistic and Slippery Slope Fallacies The Naturalistic Fallacy Empathy and Ought Restatement of the Biological Ought The Value of Naturalism The Study of Perception The Slippery Slope Fallacy Reductionism Summary xi

10 xii 3. Basic Concepts: Evolutionary Mechanisms. Basic Biological Phenomena Inheritance.... Mutation.... Natural Selection Isolation.... Genetic Drift.. Intrinsic Factors. Extrinsic Factors Natural Selection Fitness..... Sexual Recombination. Phylogeny and Ontogeny. Ethological Mechanisms. Parental Strategies.... Imprinting Experience-Expectant Structures. The Development of Bird Song. Avian Brood Parasites.... Instances of Adult Imprinting Summary Evolutionary Mechanisms and Human Behavior. Evolved Processes in Human Behavior Some Games Reproduction Plays The Interaction of Biological and Experiential Influences Some Basic Evolved Processes The Development of Human Speech and the Beginnings of Language The Development of Spoken Language. Early Stages of Language Development The Evolution of Human Language. Innateness and Social Cognition. Summary The Evolved Human Social Condition Basic Theory and Data The Environment of Evolutionary Adaptation. Contents

11 Contents xiii Patterns of Homicide Age Preferences for Mates Gender Differences in Partner Preferences 100 Sexual Strategies Theory Human Dispersal Patterns Additional Anthropological Data 105 Human Nature A Bit of History Cultural Evolution The Evolution of Morality. 109 Summary Evolutionary Psychology Genetic Determinism Cultural Variability Ideological Objections Selective Use of Evidence. 119 What Has Evolved? Basic Concepts: Moral Philosophy. Issues in Moral Philosophy. Types of Moral Theories... Basic and Derived Principles Moral Agents and Moral Patients. What Is a Person?. Rights. Value..... Justice..... Cognitive Science Rational Liberalism. Summary The Study of Moral Intuitions Biology of Morality..... Some Basic Moral Issues.. Should Numbers Count?. Empricial Studies Of Moral Intuitions

12 xiv Contents Our Initial Empirical Study Participants Methods Basic Dimensions Results Limitations Cross-Cultural Study Reanalysis of the First Study Prediction of Stated Beliefs from Scale Strength Conclusions PART II. ISSUES IN REPRODUCTION 8. Contraception, Abortion, and Infanticide: Issues and Arguments Guidelines for Argument Philosophical Concepts Biological Concepts Cognitive Concepts Definitions Moral Agents Have Personhood But All Persons Do Not Have Agency Suggested Characteristics for Personhood Arguments Regarding Personhood Problems with Viability as a Criterion The Critical Nature of Personhood Birth as a Critical Point in Human Development Early Emotional Interactions Birth as a Critical Biological Point Dworkin and the Sanctity of Life Moral Agency Tooley's Neurophysiological Criteria for Personhood and Moral Agency Characteristics of Cognitive Systems Implications Summary

13 Contents 10. Contraception, Abortion, and Infanticide: Polar Positions Positions Concerning Abortion Restrictive Abortion Arguments. Permissive Abortion Arguments. Summary.... xv Abortion: Policy Considerations Some Salient Concerns Maternal Mortality and Morbidity of Abortion. The Case of RU Psychological Effects of Abortion Guaranteeing a Minimal Life.. Thoughts Regarding Infanticide. Sexual Inequality.... Defective Fetuses.... Consequentialist Value. Policy Summary.. Moral Dimensions. Summary Reproductive Technologies... Techniques of Reproductive Assistance Artificial Insemination (AI) In Vitro Fertilization (lvf) Surrogate Mothers. Moral Issues..... Restrictive Position. Permissive Position. Cloning Human Embryos Postmenopausal Mothers. Moral Implications. Policy Implications.... Surrogate Mothers.... Policy Recommendations Regarding Surrogacy

14 xvi Contents Research Using Embryos Why Conduct Fetal Tissue Research? The Techniques Policy Questions The Slippery Slope Conclusion Epilogue Reproductive Biology Personhood Evolutionary Principles Moral Agency The Empirical Foundation Principles of Social Cognition The Abortion Debate Reproductive Technologies References Author Index Subject Index