ABOUT MYSELF:

Ph.D. York University (1975)

Research Interests: behavioural psychology, behaviour analysis, behaviourism, experimental social psychology, social learning.

Office: 6-24   Phone: (780) 492-3322   Email: dpierce@ualberta.ca

I am currently a full professor with tenure in the Department of Sociology at the University of Alberta (Canada). I am the Director of the Centre for Experimental Sociology, and retired Adjunct Professor in the Department of Neuroscience (Medicine). I also maintain an animal behaviour facility in the Metabolic and Cardiovascular Diseases Laboratory as part of the Faculty of Agriculture, Forestry and Nutritional Sciences (AFNS).

At the present time I am Fellow of the American Psychological Association, an award given for my significant contributions to the discipline of psychology. In the year 2000, I received the Faculty of Arts Research Award (Professor) for outstanding research and scholarship. In 2003, I was nominated for the Gordon Kaplin Universtiy Award for lifetime achievement in research (especially my work on activity anorexia). My research interests are broad and varied, but I have emphasized the experimental analysis of choice and preference, a bio-behavioral model of activity anorexia and the effects of reward on intrinsic motivation.

RESEARCH IN PROGRESS:

I am working with rats on the role of Pavlovian conditioning in the suppression of eating during activity anorexia (with Biondo, Heth, & Russell). I am also investigating the regulation of wheel running by the D2 dopamine system and the prevention of activity anorexia (with Biondo & Russell). In terms of human behavior, I am conducting research on the effects of rewards in coercive/autonomous social contexts for intrinsic motivation (with Banko & Cameron), on the conspicuousness of reward contingencies and attribution of credit for student achievement (with Wizniak & Cameron), and on the effects of rewards for high and low effort for intrinsic motivation (with Gear & Cameron).

SUBMITTED OR IN PREPARATION FOR PUBLICATION:

Behavior Analysis and Learning 4th edition. Mahwah, NJ: Lawrence Eralbaum Associates (in preparation with Cheney)

Blocking of conditioned taste aversion induced by wheel running during activity anorexia. Under revision for Learning & Motivation, 2006 (with Biondo, Heth, Russell & Proctor)

Food tastes associated with low energy content cause overeating by JCR-LA-cp obese-prone and lean weanling rats. Submitted to International Journal of Obesity (Heth, Owczarczyk, Russell & Proctor)

Effects of the dopamine D2 antagonist Pimizoid on wheel running during activivity anorexia. In preparation (with Biondo & Proctor).

Metabolic and endocrine correlates of activity anorexia as a function of age in JCR-LA-cp lean (+/cp) and obese-prone (cp/cp) rats. In preparation (with Heth, Proctor).

RESEARCH CONTRIBUTIONS:

BEHAVIORAL CHOICE AND PREFERENCE:

My contributions in terms of choice and preference relate to extensions of Herrnstein's matching law to human behavior, and clarification of mathematical and statistical issues related to matching theory. I have assessed matching and maximizing accounts of human behavior on concurrent schedules and helped to specify the conditions that regulate the bias and sensitivity parameters of Baum's generalized matching equation. I worked on alternative versions of the generalized matching equation (based on a mathematical elaboration of Herrnstein's proportion equation) and published on the effects of logarithmic transformations on estimates of the parameters of Baum's equation. I have published in both JEAB and JABA, as well as other journals of psychology. Some of this research is outlined in Pierce and Cheney's textbook Behavior Analysis and Learning (Lawrence Erlbaum & Associatesl, 2004). My research on concurrent schedules and human behavior, in the context of other integrative articles, helped to bridge the gap between basic behavior principles and application (applied behavior analysis). Visit the Lawrence Erlbaum & Associates website for a full description of the book, and the table of contents.

ACTIVITY ANOREXIA:

In addition to my interest in behavioral choice, I continue to maintain an active research program on an animal model of human anorexia. Together with my colleague Dr. Frank Epling (deceased), I described the laboratory conditions that induce anorexia through a combination of food restriction and excessive physical activity. I developed a theory of activity anorexia that accounts for the animal results and provides a bio-behavioral explanation for human anorexia. The laboratory model and theory are outlined in Epling and Pierce's now classic book (1991) Solving the Anorexia Puzzle: A Scientific Approach. Visit Hogrefe & Huber Publishers' website. Developments in the area of activity anorexia, eating, physical activity, nutrition, and physiology are described in Epling and Pierce's edited volume (Lawrence Erlbaum, 1996), Activity Anorexia: Theory, Research & Treatment.

I believe that the research and theory of activity anorexia qualify as significant and innovative contributions to the behavioural and biological sciences at both national and international levels. This conclusion is based on the fact that both basic and clinical researchers in a number of countries are working on the animal model of activity anorexia and testing the theoretical assumptions and hypotheses of the theory. Some of these researchers are represented in our edited volume Activity Anorexia: Theory, Research & Treatment. In addition to stimulating international scholarship, the theory of activity anorexia has generated broad-scale public interest in a bio-behavioural approach to human behaviour (see coverage by Globe and Mail, 1995; Psychology Today, 2000). I believe that the public view of behavioural science has been enhanced by our innovative analysis of human self-starvation.

REWARDS, REINFORCEMENT & INTRINSIC MOTIVATION:

There is one other research contribution that I wish to mention. In the recent past, I published with Dr. Judy Cameron an extensive meta-analysis of the effects of reward/reinforcement on intrinsic motivation. The meta-analysis appeared in the Review of Educational Research (1994) and showed that the so-called "negative effect of rewards" was limited to a circumscribed set of conditions that were easily avoided in everyday life. Other evidence in this article indicated that reward/reinforcement could be used to enhance intrinsic motivation. Generally, my research shows that reward and incentive systems can be used to promote performance in education, business and other applied settings without loss of intrinsic interest. The findings help to resolve the theoretical and practical debate between cognitive and behavioural psychology about the side effects of reinforcement contingencies. Recently, Cameron, Banko and Pierce (2001, Vol. 24, pp. 1-44) published an extensive review article in The Behavior Analyst titled "Pervasive Negative Effects of Rewards on Intrinsic Motivation: The Myth Continues". The article, with more than 5,000 downloads, reports a hierarchical meta-analysis of the literature based on 145 studies (the most inclusive meta-analysis to date). The results confirm our 1994 meta-analysis and further specified how rewards could be used effectively in applied settings. (To download article see: CAMBRIDGE CENTER FOR BEHAVIORAL STUDIES).

Based on the above article, I wrote the book (with Cameron), Reward and Intrinsic Motivation: Resolving the Controversy (2002, with Barnes Garvey Press). Visit the Greenwood Publishing Group website for a detailed description of the book and the Table of Contents. In addition, I (with Cameron) recently received a $119,500 SSHRC research grant to conduct experiments on how rewards based on achievement can be used to enhance performance and interest.

CONTRIBUTIONS TO GRADUATE TRAINING:

I have been extensively involved with the training of graduate students in terms of research for more than 20 years. As an experimental researcher, I was trained using the apprenticeship system and I have carried on this tradition of training with my own students. The basic idea of apprenticeship is that the students work closely with the professor on various research projects and utilize their training in experimental design, computer analyses of results, and communication of results in professional articles. Many of my published articles include graduate students as co-authors. I have supervised or co-supervised more than 50 graduate students' theses and dissertations in the Departments of Sociology, Psychology, Educational Psychology, Physical Education, Medicine and Neuroscience. In addition, I have served as a member on approximately 60 thesis committees. Many of my students have obtained academic positions and I continue to write to them, see them at conferences, and work on research projects with them. Sarah-Jeanne Salvy from the University of Quebec at Montreal (Young Scientist Award Winner, 2000) worked with me on experiments concerned with conditioned taste aversion and activity anorexia from 2000-2003. Under my supervision Sarah won the APA Dissertation Award (Division 25) for 2003 and obtained a post-doctoral SSHRC fellowship at the University of Toronto, 2004. I am currently supervising animal research on activity anorexia with my doctoral student Mia Biondo, and co-supervising (with Heth, Psychology and Cameron, Educational Psychology) research on aspects of rewards and intrinsic motivation with doctoral students Katherine Banko, Amber Gear, and Ronda Wizniak. As a final point I wish to mention my contribution to research in the graduate program of Sociology. During my tenure as Associate Chair Graduate, I instituted a one-day conference for graduate student research (Research Day). This conference was implemented to encourage graduate students to prepare for and give professional presentations. Graduate students learn how to stay on topic, select audio-visual material to highlight their presentations, speak with a voice of confidence, and make their points within a circumscribed time limit (10 minutes). Research Day has continued over the years and is now a formal part of our graduate program. In 2001, the Department of Sociology renamed the event in my honor as the W. David Pierce Research Colloquium, and a $200 Annual Pierce Prize is given for the most outstanding student presentation. Overall, I have made important contributions to graduate research and I continue to view graduate research and education as a central part of my academic interests.

RECENT PUBLICATIONS:

The following is a selected list of publications and reviews.

BOOKS:

Pierce, W. D. & Cheney, C. D. (2004). Behavior Analysis and Learning 3rd ed. Mahwah, NJ: Lawrence Erlbaum Associates. [509 printed pages]

Cameron, J. & Pierce, W. D. (2002) Rewards and Intrinsic Motivation: Resolving the Controversy. Bergin & Garvey Press. [255 printed pages]

Pierce, W. D. & Epling, W. F. (1999). Behavior Analysis and Learning 2nd ed. Upper Saddle River, NJ: Prentice Hall. [444 printed pages]

Epling, W. F. & Pierce, W. D. (Eds., 1996). Activity anorexia: Theory, research & treatment. New Jersey, Lawrence Erlbaum. [239 printed pages]

Pierce, W. D. & Epling, W. F. (1995). Behavior Analysis and Learning. Englewood Cliffs, NJ: Prentice Hall. [484 printed pages]

Mellof, W. & Pierce, W. D. (Eds., 1994). Introduction to Sociology. Toronto: Nelson Canada. [460 printed pages]

Epling, W. F. & Pierce, W. D. (1991). Solving the anorexia puzzle: A scientific approach.. Toronto: Hogrefe and Huber. [229 printed pages]

CONTRIBUTIONS TO BOOKS:

Pierce, W. D. (2000). Behaviorism. In E. F. Borgatta (Ed.), Encycolpedia of Sociology (pp. 208-216). New York: Macmillan.

Pierce, W. D., & Epling, W. F. (1997). Activity Anorexia: Interplay of culture, behavior and biology. In P. A. Lamal (Ed.), Cultural Contingencies: Behavior analytic perspectives on cultural practices (pp. 53-85). New York: Praeger.

Krull, C., & Pierce, W. D. (1997). Behavior analysis and demography: Incentive control of fertilityin the province of Quebec, Canada. In P. A. Lamal (Ed.), Cultural Contingencies: Behavior analytic perspectives on cultural practices (pp. 107-132). New York: Praeger.

Pierce, W. D. & Epling, W. F. (1996). Theoretical developments in activity anorexia. In Epling, W. F. & Pierce, W. D. (Eds.), Activity anorexia: Theory, research & treatment. New Jersey, Lawrence Erlbaum.

Epling, W. F. & Pierce, W. D. (1996). Overview of activity anorexia. In Epling, W. F. & Pierce, W. D. (Eds.). Activity anorexia: Theory, research & treatment. New Jersey, Lawrence Erlbaum.

REFEREED ARTICLES:

Heth, CD & Pierce, WD. (2006, accepted) The role of pre-exposure to novel food tastes in activity-based conditioned taste avoidance. Learning & Motivation (20 pages).

Belke, T.W., Pierce, W.D., & Duncan, I.D. (2006) Reinforcement value and substitutability of sucrose and wheel running: Implications for activity anorexia. Journal of the Experimental Analysis of Behavior, 86, 131-158.

Biondo, M., Pierce, W. D., Heth, C. D., Proctor, S., & Russell, J.C. (2005). Pavlovian learning and activity anorexia. Proceedings of the Alberta Mental Health Research Showcase, Banff, AB, (abstract p. 69).

Cameron, J., Pierce, W. D., Banko, K. M. , & Greer. A (2005). Achievement-based rewards an intrinsic motivation: A test of cognitive mediators. Journal of Educational Psychology, 97, 641-655.

Cameron, J., & Pierce, W. D. (2005) Rewards and motivation in the classroom. Academics Exchange Quarterly, 9, 67-71.

Salvy, S., Pierce, W.D., Heth, C.D., & Russell (2004). Taste avoidance induced by wheel running: Effects of backward pairings and robustness of conditioned taste aversion. Physiology and Behavior, 82, 303-308.

Cameron, J., Pierce, W. D., & So, S. (2004, accepted). Rewards, task difficulty, and intrinsic motivation: A test of learned industriousness theory. Alberta Journal of Educational Research.

Belke, T. W., Pierce, W. D., & Jensen, K. (2004). Effect of short-term prefeeding and body weight on wheel running an responding reinforced by the opportunity to run in a wheel. Behavioral Processes. 67, 1-10.

Salvy, S., Pierce, W. D., Heth, C.D., & Russell, J. C. (2004). Conditioned taste aversiom induced by wheel running: Further evidence on wheel running duration. Behavioural Processes, 66, 101-106.

Salvy, S., Pierce, W. D., Heth, C.D. , & Russell, J. C. (2003). Wheel running produces conditoned food aversion. Physiology and Behavior, 80, 89-94.

Pierce, W. D., Sydie, R. A., Stratkotter, R., & Krull, C. (2003). Social concepts and judgments: A semantic differential analysis of the concepts feminist, man and woman. Psychology of Women Quarterly, 27, 338-346.

Pierce, W. D., Cameron, J., Banko, K. M., & So, S. (2003). Rewards, performance standards, and intrinsic motivation, The Psychological Record, 53, 561-579.

Pierce, W. D. & Cameron, J. (2002). A summary of the effects of reward contingencies on interest and performance. Behavior Analyst Today, 3, 221-228.

Salvy, S., Pierce, W. D., Heth, C.D. , & Russell, J. C. (2002). Pre-exposure to wheel running disrupts taste aversion conditioning. Physiology and Behavior, 76, 51-56.

Heth, C. D., Inglis, P., Russell, J. C., & Pierce, W. D. (2001) Conditioned taste aversion induced by wheel running is not due to novelty of the wheel. Physiology & Behavior, 74, 53-56.

Cameron, J., Banko, K. M., & Pierce, W. D. (2001). Pervasive negative effects of rewards on intrinsic motivation: The myth continues. The Behavior Analyst, 24, 1-44.

Pierce, W. D. (2001). Activity anorexia: Biological, behavioral, and neural levels of selection. Behavioral and Brain Sciences, 24 (3), 551-552.

Eisenberger, R., Pierce, W. D., & Cameron, J. (1999). Effects of reward on intrinsic motivation: Negative, neutral, and positive. Psychological Bulletin, 125, 677-691.

RECENT PRESENTATIONS:

I have made numerous invited presentations at professional meetings including: The Learned Societies, Canadian Physiological Society, American Sociological Association, American Psychological Association, the Association for Behavior Analysis, Canadian Association for Animal Laboratory Science, Pacific Coast Fertility Society, the Endocrine Society, the British Psychological Society, and the Inter-American Congress of Psychology. I have given a number of invited presentations over the years including an address to the American Psychological Association.

REFEREED PRESENTATIONS:

Wiznaik, R.L, Gear, A.L., Pierce, W.D., & Cameron, J. Direct and meaning-based reading programs: Effects on teachers’ratings of student performance. Annual Meetings of the Association for Behavior Analysis, Atlanta, GA, May 28, 2006.

Gear, A.L., Wiznaik, R.L, Cameron, J., & Pierce, W.D. Learned industriousness and intrinsic motivation: Effects of rewards for effort on task involvment. Annual Meetings of the Association for Behavior Analysis, Atlanta, GA, May 28, 2006.

Lynch, S.L., Banko, K.M., Cameron, J., & Pierce, W.D. Reward contingencies and personal freedom: Effects on intrinsic motivation and performance. Annual Meetings of the Association for Behavior Analysis, Atlanta, GA, May 28, 2006.

Biondo, M., Pierce, W. D., Heth, C. D., Proctor, S., & Russell, J.C. Pavlovian learning and activity anorexia. Alberta Mental Health Research Showcase, Banff, AB, Nov. 28 to 30, 2005.

Biondo, M., Pierce, W. D., Heth, C. D., Proctor, S., & Russell, J.C. Pavlovian blocking and activity anorexia. Annual Meetings of the Association for Behavior Analysis, Chicago, Illinois, May 29, 2005.

Banko, K., Pierce, W. D. & Cameron, J. Effects of reward contngencies on performance and intrinsic motivation depend on interpersonal context. Annual Meetings of the Association for Behavior Analysis, Chicago, Illinois, May 30, 2005.

Cameron, J. & Pierce, W. D. Performance-based rewards, cognitive processes, and intrinsic motivation. Annual Meetings of the American Educational Research Association, Montreal, Quebec, April 10, 2005.

Biondo, A.M., Pierce, W.D., Heth, C.D., & Russell, J.C. Development of activity anorexia may not depend on Pavlovian conditioning. Proceedings of the 27th Annual Meeting of the Canadian College of Neuropsychopharmacology, Kingston, Ontario, May 29th - June 1st 2004.

Belke, T., Pierce, W. D., & Duncan, I. Concurrent wheel-running and sucrose reinforcement: Effects of sucrose concentration manipulation. Annual meetings of the Association for Behavior Analysis, Boston, May 30, 2004

Cameron, J., & Pierce, W. D. Rewards and intrinsic motivation: A test of cognitive mediators. Annual meetings of the Association for Behavior Analysis, Boston, May 30, 2004

Salvy, S., Pierce, W. D., Heth, C. D., & Russell, J. C. Taste avoidance induced by wheel running: Effects of backward pairings and robustness of CTA. Annual meetings of the Association for Behavior Analysis, Boston, May 30, 2004

Biondo, M., Pierce, W. D., Heth, C.D., & Russell, J. C. A test of a blocking procedure in an animal model of activity anorexia. Annual meetings of the Association for Behavior Analysis, Boston, May 30, 2004

Biondo, M., Pierce, W. D., Heth, C.D., & Russell, J. C. Excessive running by food restricted rats: A model of activity anorexia. Annual meetings of the Canadian College of Neuropsychopharmacology, Montreal, June 3, 2003

Biondo, M., Pierce, W. D., Heth, C.D., & Russell, J. C. Suppression of familiar food intake by wheel running in a model of activity anorexia. Annual meetings of the Canadian College of Neuropsychopharmacology, Montreal, June 3, 2003.

Mandrusiak, M., Russell, J. C., Heth, C. D., & Pierce, W. D. Can activity anorexia in rats be used as a model for human anorexia? Annual meetings of the Association for Behavior Analysis, San Francisco, May 25, 2003.

Salvy, S., Pierce, W. D., Heth, C. D., & Russell, J. C. Operant and respondent processes in activity anorexia. Annual meetings of the Association for Behavior Analysis, San Francisco, May 25, 2003.

Pierce, W. D., & Cameron, J. Intrinsic motivation and the effects of achievement-based rewards during learning and testing. Annual meetings of the Association for Behavior Analysis, San Francisco, May 25, 2003.

Salvy, S., Pierce, W. D., Heth, C. D., & Russell, J. C. Activity anorexia: The interrelation of operant and respondent processes. Annual convention of the American Psychological Association, Chicago, IL: August 25, 2002.

Cameron, J., So, S, Banko, K. M.,Gear, A, & Pierce, W. D. Positive effects of reward and effort on motivation and performance. Annual meetings of the Association for Behavior Analysis, Toronto, May 23-28, 2002.

Banko, K.M., Cameron, J., & Pierce, W. D. The role of experimenter.expectations and reward on intrinsic motivation. Annual meetings of the Association for Behavior Analysis, Toronto, May 23-28, 2002.

Salvy, S., Pierce, W. D., Heth, C. D., & Russell, J. C. Conditioned taste aversion induced by wheel running is not dose sensitive. Annual meetings of the Association for Behavior Analysis, Toronto, May 23-28, 2002.

Pierce, W. D., Heth, C. D., Inglis, P., & Russell, J. C. Conditioned taste aversion induced by wheel running is not due to novelty stress. Annual meetings of the Association for Behavior Analysis, New Orleans, May 26, 2001

Banko, K., Cameron, J., & Pierce, W. D. Do rewards decrease intrinsic motivation? An analysis of contraditory findings. Annual meetings of the Association for Behavior Analysis, New Orleans, May 27, 2001.

So, S., Banko, K., Pierce, W. D. , & Cameron, J. Increasing motivation and interest through rewards based on challenge and mastery. Annual meetings of the Association for Behavior Analysis, New Orleans, May 27, 2001.

Belke, T. W., & Pierce, W. D. Pre-feeding reduced the reinforcement effectiveness of wheel running in rats. Annual meetings of the Association for Behavior Analysis, New Orleans, May 28, 2001.

INVITED PRESENTATIONS:

Pierce, W. D., & Cameron, J. Positive effects of performance-based rewards on measures of intrinsic motivaton. International symposium on "Battling the myth: Effects of reward on perceived self-determination, intrinsic task interest, and creativity;" Annual meetings of the Association for Behavior Analysis, San Fransisco, May, 2003.

Cameron, J., & Pierce, W. D. A socio-historical analysis of the rewards and intrinsic motivation controversy. Annual meetings of the Association for Behavior Analysis, New Orleans, May 27, 2001.

Cameron, J., & Pierce, W. D. Intrinsic motivation and rewards: Where do we stand? Invited presentation to the California Association for Behavior Analysis, San Fransisco, February 4, 2000.

Pierce, W. D. Activity anorexia: Clinical implications for health professionals. Invited workshop for the California Association for Behavior Analysis, San Fransisco, February 4, 2000.

Pierce, W. D. Activity anorexia: The interplay of culture, behavior and biology. Invited presentation to Faculty of Education, Monash University, Melbourne, Australia, April 1, 1999.

Pierce, W. D. Activity anorexia: biological and behavioral determinants. Invited presentationto Department of Psychology, University of Otago, Dunedin, New Zealand, March 8, 1999.

GRANTS:

SUBMITTED:

Telemetry monitoring equipment to understand behavioral components of nutrition and metabolism. NSERC equipment grant application. October, 2006 (with Proctor).

RECEIVED:

Overeating, obesity and anorexia. Operating grant for new behavioural laboratory from VP(Research) and Faculty of Arts/Sociology, May 1, 2006, $48,000.

Pre-exposure to novel foods, conditioned taste aversion, and activity anorexia. Support for Advancement of Scholarship Fund (SAS), May 1, 2005. $6600.

VP (research) and Faculty of Arts grant to establish a behavioural research facility as part of the new Metabolic and Cardiovascular Diseases Laboratory in Agriculture, Forestry & Nutrition Sciences (AFNS) at the University of Alberta, May, 2004, $20,378.

Enhancement of intrinsic motivation by tying rewards to level of achievement during learning and testing. SSHRC operating grant, 2003-2005, $119,500 (with Cameron).

Activity anorexia: extending conditioned taste aversion induced by wheel running to food stimuli. Vice President Research (Arts, VP Research, Sociology) operating grant, January, 2003, $5400.

Activity anorexia: The role of conditioned taste aversion induced by physical activity. Support for Advancement of Scholarship Fund (SAS), October, 2000, $6447.

Experimenter expectations and the effects of reward on students' intrinsic motivation. Support for the Advancement of Scholarship Fund (SAS), November, 2000, $3,900. (with Cameron).

Pierce, W. D. (member of team of 8 researchers from different universities and hospitals including Katzman, Davis, Forget, Meilleur, Wilkins, and Salvy and coordinator Jean-Yves Frappier). Troubles des conduites alimentaires: Vers de nouvelles frontieres. Canadian Institute for Health Research (CIHR), April, 2000. $24,000.

Cultivating interest and performance through rewards based on challenge, mastery and effort. Social Sciences and Humanities Research (SSHRC) Grant, April, 1998, $61,000. (with Cameron)

Behavioral and physiological determinants of activity anorexia, Alberta Mental Health Research Fund, $50,000, 1995. (with Epling & Russell)

RECENT MEDIA COVERAGE:

CBC News Magazine on rewards and intrinsic motivation (Ontario Today with Laurie Fung) June 24, 2003.

Smart Money: A magazine of Wall St. Journal (Perks gone bad) March, 2003.

Fitness Magazine (Activity Anorexia) January, 2002.

Globe & Mail (When rewards don't work), September 25, 2002.

CBC Morningside (Activity Anorexia) April 9, 2001.

National Post (Research vindicates bribery as school tool) June 20, 2001.

Edmonton Journal (Bribery key to better grades) June 21, 2001.

BBC World News (Cameron on our rewards and motivation research) June 22, 2001.

National Post (When it pays to get good marks) June 29, 2001.

Psychology Today (Killer workout: The dark side of diet and exercise) May/June, 2000.

All website content is the property of this site; and subject to Copyright © 2004

Contact - Dr. W. David Pierce