In Appreciation: Hershel W. Leibowitz

Herschel W. Leibowitz

Herschel W. Leibowitz

APS Fellow and Charter Member Hershel W. Leibowitz died February 13, 2011 at the age of 85.

Leibowitz was the Evan Pugh Professor of Psychology at Pennsylvania State University until his retirement in 1995. He made significant contributions to the study of visual perception and pioneered the integration of basic and applied psychological research.

Before joining the Penn State faculty in 1962, Leibowitz earned his BA at the University of Pennsylvania and his MA in Experimental Psychology and his PhD in Physiology at Columbia University. He taught at the University of Wisconsin from 1951 to 1960 and then served as advisory psychologist and manager of behavioral research at IBM from 1960 to 1962.

Leibowitz authored more than 250 articles in scientific journals and wrote a widely used textbook on visual perception (Leibowitz, 1965). He garnered many awards, including the American Psychological Association’s Distinguished Scientific Contribution Award for the Applications of Psychology (1994), an Honorary Doctor of Science from the State University of New York (1991), the American Academy of Optometry Prentice Medal (1987), and the Pennsylvania Optometric Association Van Essen Award (1987).

A Festschrift for Leibowitz, edited by three of his former students, Jeff Andre, D. Alfred Owens, and Lewis Harvey (2003), conveys the richness and diversity of the science that Leibowitz pursued and fostered in others. The appreciation that follows reflects only in miniature the esteem with which he was held and the affection he enjoyed.

Jeffrey Andre

James Madison University

I was Hersh’s last graduate student, receiving my PhD from Penn State in the summer of 1995. Like the students before me, I found Hersh to be a master teacher. His lessons didn’t always take the form of lectures and diagrams. Some were given on ice cream walks to the PSU Creamery, around a dinner table at a conference, or simply while sitting in his office in Moore Building after one of his runs.

Perhaps the most important lesson I learned from Hersh was to think independently. Hersh’s favorite question, designed to encourage independent thinking, was deceptively simple: “Why is that important?” The question was thought-provoking. It made me think about how my research fit into a bigger picture, and it forced me to think about how I should do the best science I could.

The independent thinking that Hersh taught me came in handy when I prepared for my comprehensive exams. At that time, in 1994, Hersh had his first heart problems, and he was in a coma for a few days. Nevertheless, with steady resolve and with his wife, Eileen, by his side, he showed up for my comprehensive exams and later for my dissertation proposal.

Hersh and Eileen always treated me and other students as part of their family. They freely offered respect, love, caring, and, most of all, support. For that, I am extremely grateful. All of us who worked with Hersh feel the same way.

Irving Biederman

University of Southern California

Hersh was a visiting professor one summer while I was a graduate student at the University of Michigan where he taught a one-hour course in perception. It was an extraordinary experience, with simple, powerful insights coupled with demonstrations that he would cobble together out of scraps of paper or plastic.  I remember especially well him showing us the Pulfrich effect in which a pendulum (a pencil suspended by a string) swinging perpendicular to the line of sight appears to follow an elliptical path when viewed with some darker transparent plastic held over one eye.

Hersh had uncovered a size-velocity illusion in which bigger things appear to move more slowly than little things (Leibowitz, 1985), so I wasn’t surprised years later to learn that elephants run about as fast as rabbits. A life and death application of this illusion that Hersh noted is that drivers often think they can beat trains (big things) to railroad crossings. Forty years later the Los Angeles Times featured this illusion after a rash of such fatalities with the new commuter trains.

Hersh’s brief perception course carried me a long way. All of us in the course loved Hersh’s casual, gentle, informal style. The students thoroughly enjoyed his participation, with his son, at our weekend softball games. Indeed, he will be missed.

Richard A. Carlson

Pennsylvania State University

For ten years, I had the office next to Hersh Leibowitz. I met him on my first day in the office, arriving there as a new assistant professor. He stopped by to ask if I’d been to the Penn State Creamery. When I told him I hadn’t, he insisted that he take me there and buy me an ice cream cone. As we strolled around campus eating our ice cream and chatting, Hersh suddenly stopped and said, “Hmm, I don’t recognize where we are. Do you think you can find the way back to our building?” We made it back, and to this day I don’t know whether he was kidding or not. I’ll never forget his kindness in trying to make me feel at home.

Being Hersh’s office neighbor was often entertaining. He told me jokes nearly every day — often jokes he’d told me many times before. He was fond of stopping by to ask if I was lost in thought because, he said, “You’re a cognitive psychologist, aren’t you?” Hersh was also fond of stopping by to tell me about something interesting he’d read or had learned in the lab. I got to see first-hand his devotion to his graduate students, and in turn their devotion to him. I also got to observe some of his experiments as they took place in the hallway (the only space long enough!). Being next to or actually surrounded by his active lab was a great learning experience for me.

Before I came to Penn State, one of my graduate student mentors described Hersh as “a man with a huge heart.” Truer words were never spoken.

Richard Held

MIT & New England College of Optometry

I am happy to contribute to a remembrance of Hersh. He was always so friendly, warm, and positive in his outlook that it was a pleasure to be with him. But that pleasure was really a bonus over and above his value as a consultant who provided a source of knowledge and method governing our research. In retrospect, I am sure he assured us of at least one grant with his excellent advice. But all his scientific and educational talents aside, he was loveable, and had a propensity for corny jokes, like the sad tale of two peanuts who wandered down a dark alley. What happened? One was a salted. Then there was the famous occasion when Hersh expounded on the joys and glories of teaching psychology. He ended by declaring with a glint in his eye, “You even get paid for it!”

Robert Hennessy

Monterey Technologies, Inc.

Hersh believed that the capstone of science is communication of methods and findings to colleagues and others at large. He took this to heart by publishing frequently, often in general-interest journals or popular media. A perusal of his publications reveals a diversity of outlets; he had no pet journal. A constant value that was expressed in all his work was to make his research results and implications simple, clear, and understandable. He instilled this value in his students. “No one will ever complain if you make it simple,” he told them.

On a personal level, Hersh expected his graduate students, from day one, to start thinking about, and eventually to submit, papers for presentation at conferences. The lesson was clear: The research program was not complete until the results are disseminated. Given the location of Penn State, the annual meeting of the Eastern Psychological Association was the principal venue for presentations. Understandably, most of us at first were as apprehensive about presenting at EPA as we were about going to our first prom. But Hersh, in his kind and subtle way with all things, encouraged and mentored us through this process.

Learning from, and just being around Hersh had a profound, lifelong influence on my work, my relations to other people, and my general sense of place. He was the dearest and wisest man I ever met. I will miss him. The best tribute I and his other students can pay him is to bring the illumination of his personal and professional worldview forward to recognize and resolve problems, discover new things, and educate and improve the lives of others. If we fail to do this, we will find ourselves in the dark. There, as Hersh pointed out, you can’t see a damn thing.

Chris A. Johnson

University of Iowa

When I arrived at Penn State as a graduate student, Hersh involved me in a research project on motion detection in the peripheral visual field. The question was whether correcting refractive errors in the peripheral visual field would improve motion detection. We found that it did, and we submitted the paper to Science, where it was accepted after minor revision (Leibowitz, Johnson, & Isabelle, 1972). A few months later, a letter was submitted to Science about our results. The letter writer claimed to be unable to replicate our findings. I was furious and went to Hersh’s office, hoping to learn how we could get even with this nogoodnik.

Hersh calmly suggested that we call the fellow. I resisted at first, feeling like this was consorting with the devil, but we made the phone call, and during the call Hersh suggested that the other researcher bring his subjects to Penn State to be tested on our equipment and that we bring our subjects to his lab for them be tested there. The exchange occurred and as a result we learned that correcting refractive error does improve motion detection

LeiboFest 2007. Front row (L to R): Bob Hennessy, Ken Shiina, Eileen and Hersh Leibowitz, Fred Owens, Chris Johnson. Back row (L to R): Julian Thayer, Larry Guzy, David Williams, Inger Lindblad-Williams, Malcolm Cohen, Ellie Francis, Justin Owens, Rick Tyrrell, Johnell Brooks.

LeiboFest 2007. Front row (L to R): Bob Hennessy, Ken Shiina, Eileen and Hersh Leibowitz, Fred Owens, Chris Johnson. Back row (L to R): Julian Thayer, Larry Guzy, David Williams, Inger Lindblad-Williams, Malcolm Cohen, Ellie Francis, Justin Owens, Rick Tyrrell, Johnell Brooks.

but it does not improve peripheral visual acuity. The letter to the editor appeared in Science along with our reply, and we eventually produced several collaborative papers that reconciled the differences from our laboratories and led us jointly to other insights.

I learned several things from this experience: (1) first impressions are not always accurate; (2) it is better to be patient than impulsive; (3) humility is a virtue and achieves more than arrogance; (4) collaboration is better than conflict. These are just some of the things I learned from Hersh. Nearly 40 years later, hardly a day that goes by that I don’t think of him or one of his pearls of wisdom. I can truly say that Hersh has been a dominant force in my development. Every day, I try to provide a similar experience for the younger investigators who come through my own lab.

Mel Mark

Pennsylvania State University

We all know a colleague or student whose scholarly interests seem to derive from a personal shortcoming. Indeed, the term “mesearch” was created as a label for such cases. For Hersh Leibowitz, the opposite applied. Best known for his work on human vision, including its application to driving and safety more generally, Hersh’s vision, his truly human vision, was as good as it gets.

Hersh, first of all, had the vision to engage with his beloved wife Eileen in a great lifelong partnership. He saw how to give priority to his family, even while he invested the time and energy for a truly distinguished career. As a key part of that career, Hersh had the vision to integrate the so-called basic and applied. Hersh was truly translational before translational research became fashionable. Whether he knew it or not, Hersh inspired others to do the same.

Hersh also had a clear vision of what a senior colleague could do to make a junior faculty member, even one with very different research interests, feel welcome. Part of this was to treat new colleagues like he treated more senior colleagues, or actually like he treated everyone — with kindness, with respect, with generosity in action and attribution, and as an audience for his ceaseless jokes. Perhaps not all who knew Hersh would apply the term “vision” to his humor, but they laughed, and Hersh saw well the value of laughter in our daily lives and social networks. Whether with a joke, a small act of kindness, or an encouraging comment, Hersh always saw the best in others.

Raymond S. Nickerson

Tufts University

I knew Hersh as a consequence of serving with him on the U.S. National Research Council’s Committee on Human Factors and communicating with him as a member of the founding editorial board of Journal of Experimental Psychology: Applied when I edited that journal. Even with this limited interaction, he made a great impression on me. He was very bright, gracious, unassuming, and had a wonderful sense of humor. He was one of very few people who had two separate long stints on the NRC’s Committee on Human Factors (now the Board on Human–Systems Integration). Many members serve for two consecutive 3-year terms, but very few are asked to serve again later, after rotating off. Hersh was on the initial committee (chaired by Dick Pew) when it was established in 1980, and was on again when I arrived in 1988. He was a delightful colleague, full of sound practical advice and good humor. His supply of puns and witticisms was endless. He was an impressive and humble man. The world could use many more like him.

D. Alfred Owens

Franklin & Marshall College

“Hersh liked everybody … and everybody liked Hersh.” That was the refrain of Michael Leibowitz’s loving and humorous eulogy to his departed father. Hersh had a way of making everyone feel comfortable and interested and important. He had a playful disposition, a proclivity for silly joke, and hilarious pranks. It seemed as though he couldn’t help it. He just liked having fun. And those around him picked up his mannerisms and phrases. Hersh liked all of us … and all of us liked Hersh.

Students were inspired by Hersh’s lessons about how to choose good questions, the value of an open attitude toward unfamiliar ideas, the hazards of “falling in love” with ideas, and the desire to contribute research that makes a positive difference outside one’s academic specialty. Hersh pressed us to respect simple facts as much as complex abstractions and to appreciate the historical along with the most recent research. One of our favorite lessons was Leibowitz’s First Law: “You can’t see a damn thing in the dark!”

Hersh championed the view that basic and applied science have a “symbiotic” relationship (Leibowitz, 1996), meaning that persistent practical problems are fundamentally interesting because they expose gaps of understanding. Thus, practical matters can be a useful guide for devising more fruitful research. From his perspective, no model or theory — no matter how clever — is self-justified. Every new finding and every idea had to face Leibowitz’s constant question, “Why is that important?” Hersh created a lively and purposeful intellectual environment, one that many of us strive to pay forward.

Leibowitz’s influence and inquiries extended far beyond his students. He numbered among the most frequently cited contributors to the literature in perception (White, 1987). His network of collaborations extended from coast to coast, from Europe and Africa to Australia and Japan, from Anthropology to Zoology. He took pride in the fact that, over the span of his career, he never spent a sabbatical at a psychology department. Hersh’s diverse collaborations were highly productive. His work with an anthropologist revealed fascinating cross-cultural differences in the strength of visual illusions (Kilbride & Leibowitz, 1975). His long-standing association with optometrists sparked ground-breaking research on the eyes’ focusing behavior (Hennessy & Leibowitz, 1971, 1972), as well as the demonstration that many people experience myopia and visual fatigue in difficult visual conditions because their oculomotor adjustments shift toward an intermediate resting posture (Andre, 2003; Leibowitz & Owens, 1975, 1978; Owens, 1984; Tyrrell & Leibowitz, 1990). His collaboration with colleagues in athletics and kinesiology yielded research on peripheral vision (Leibowitz, Johnson, & Isabelle, 1972), including implications for the abilities of elderly individuals walking on stairs (Simoneau, et al., 1991). His collaborations with neuroscientists built upon the powerful concept of two visual systems to clarify a wide range of phenomena, from anomalies in motion perception (Post & Leibowitz, 1985) to visually guided behavior (Tyrrell, Rudolph, Eggers, & Leibowitz, 1993) to a novel theory of why motorists do not recognize the limitations of their vision when driving at night (Leibowitz, Owens, & Tyrrell, 1998). This is only a small sample filtered through my personal lens. Many more can be found in our Festschrift volume (Andre, Owens, & Harvey, 2003).

David A. Rosenbaum

Pennsylvania State University

The first time I met Hersh was when I gave a couple of talks at Penn State shortly after I had received my PhD at Stanford and was working at Bell Labs in Murray Hill, New Jersey. Hersh made me feel very comfortable and appreciated in those talks, given early in my career. He boosted my confidence tremendously by smiling and nodding more than anyone could have reasonably be expected to, especially considering that the work I was presenting still needed quite a bit of refinement, as I knew and as Hersh undoubtedly did as well.

Many years later, I returned to Penn State for a job interview. Hersh took me to lunch. He gave little hint that he was interviewing me. Again, he made me feel completely at ease and comfortable, but by the end of the meeting, it was evident he had drawn quite a bit out of me.

Hersh was equally kind to my wife, Judith Kroll, who also interviewed at that time for another spot on the Penn State faculty. Judy, who is now director of Penn State’s Center for Language Science, was terrified of the tiny plane that she and I took to State College and would have to take again when we flew out of the local airport. Hersh told her calmly and confidently that if she sat right above the wing, she’d be all right. She and I followed his advice. His tone and expertise reassured Judy enough to convince her that it would be all right to take many such flights.

Judy and I were pleased to get job offers from Penn State, but our arrival at PSU was marred by Hersh’s change of health. I had looked forward to working with him, my area of study being the control of action and one of his many specialties being the integration of perception and action. But he had his massive coronary before we moved to State College, rendering him unable to continue at his previous fever pitch. I can only dream of the many things I might have learned from Hersh had he and I been able to work together.

Despite his being less visible in the department during his prolonged illness, Hersh continued to contribute to the department, to Penn State University, and to our community through his and his wife Eileen’s extraordinary philanthropy. He and Eileen gave very generously to all of these, not just financially but also in terms of their time and energy. Each fall, the Psychology Department hosts major speakers who are brought in, thanks to the lecture series that Hersh and Eileen sponsored. At the recent ceremony marking the start of construction of a new addition to and renovation of our Psychology Department’s Moore Building, Hersh was one of the people invited to wield a ceremonial spade to help launch the work. Finally, in 2003, Hersh and Eileen were named State College’s Renaissance Man and Woman of the Year. This major honor in our community was given for their active involvement and philanthropy with many local cultural, political, educational, and service organizations. This signal honor was a tall tribute to these two remarkable people who, as a team as well as on their own, touched so many lives.

Ken Shiina

Bunkyo University, Japan

Hershel W. Leibowitz was the first non-Japanese psychologist I ever met. In the summer of 1965, four years before I became a graduate student of Hersh’s at Penn State, I attended a talk that Hersh gave at Tokyo University. About 30 people attended, and I was the only undergraduate among them. I was already familiar with his work on motion perception because I had been working on that topic for my undergraduate thesis. I was struck by how modest this great scientist was.

Later, I joined Hersh’s lab and had the privilege of giving a talk about research I was doing with him. This was my first study using laser optometry to study size perception and accommodation. After I presented the data at the meeting (EPA, held in 1970 in Atlanta), someone asked me, “What happens to size perception when you get old?” I couldn’t answer. Recognizing this, Hersh stood up and said to the questioner, “You will know soon enough.” The room erupted in laughter.

In 2003, many years after I completed my studies with Hersh, I returned to State College and visited his home. He and Eileen welcomed me with open arms. To my delight, I saw that, despite all that he had gone through health-wise, was still able to recall the Japanese phrases he had learned nearly 40 years earlier for his visit to Tokyo.

Hersh always took other people’s feelings into account. Although I learned a tremendous amount about vision from Hersh, what I learned the most came from his humanity.

Rick Tyrrell

Clemson University

Hersh was a passionate believer in the usefulness of Psychology. I first saw this passion when I served as Hersh’s teaching assistant. On the first day of class, he asked the students their opinions about what qualified as the world’s biggest problems. After compiling a long list on the chalkboard, he asked the students “to which of these problems is behavior relevant?” The students gradually came to realize that behavior was relevant to nearly all the world’s problems. Hersh drove home the point by exclaiming, “Isn’t this an exciting time to be studying Psychology?” I was moved by this exercise and have repeated it in my own classes.

Hersh didn’t just talk about Psychology being useful, he made sure of it. There’s probably no better example of how he could weave together basic and applied science than his selective-degradation hypothesis (Leibowitz & Owens, 1977). According to this hypothesis, the neural pathways that support visually guided locomotion are so robust that, even in low illumination, drivers find it so easy to steer their vehicles well that they become complacent, falsely believing they can see everything that needs to be seen. Three elements of the idea are striking. First, it has legs: More than 30 years after its inception, the idea is still used to generate predictions that continue to be supported. Second, Hersh’s hypothesis is so compelling that when students learn about it, their nighttime safety increases (Tyrrell, Patton, & Brooks, 2004). Third, the idea was borne of Hersh’s reading about an emerging development in neurophysiology — the possibility that mammals have two functionally distinct visual systems (what Hersh called the focal and ambient systems). Who besides Hersh could have read Schneider’s (1967) research on the wiring of hamster brains only to walk away with insights about night driving and then have those insights still being proven useful three decades later?

Hersh was a genuine “big shot,” but he was never arrogant, pushy, or demanding. Instead, he was characteristically playful and even goofy. Hersh taught us that being successful did not require taking yourself too seriously. I can still see Hersh plodding into the Psychology Department office wearing his sweaty running clothes and demanding that the Head implement a dress code. He also campaigned for the department to develop a Museum of Cognitive Models.

Anyone interested in reading other remembrances of Hersh or in leaving a message should visit


I’ve truly enjoyed reading about the influence of Hersh on all of the contributors. Thank you so much for sharing.

Thank you to all who contributed. And to all who have expressed their condolences and shared their memories. Dave, we sure appreciate the lead you took for this article.

You may have never heard Leibowitz’s 5th law: “Don’t be a stranger. Just be strange”

Let’s all honor him by being a bit more strange every day! After all, isn’t that why you are psychologists?


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