It is our pleasure to edit this special issue of Behavior Genetics based on the Festschrift for John Loehlin held at the 2011 annual meeting of the Behavior Genetics Association in Newport, Rhode Island. The idea for this Festschrift was first discussed between us 10 years earlier at a small conference on Developmental Behavior Genetics in Pittsburgh. During our conversation it became obvious that, in contrast to the several leaders of the field of Behavior Genetics who had recently had Festschrifts held for them, John Loehlin had not. We felt that this was a tragic omission, one that should be rectified. After a series of discussions over the course of several years we were able to bring this idea to fruition.

Turkheimer’s experience

Our reasons for organizing this Festschrift differed somewhat. One of us (ET) worked with, took classes from, and was directly influenced by John Loehlin during graduate school in Psychology at the University of Texas. I had arrived for graduate school completely unprepared for what I faced, and absolutely unready to make use of the gifts John had to offer. I knew nothing of individual differences—the strongest intellectual strain growing in Austin at the time—or of behavior genetics. John was Chair of the Department, and my first memories of him involve a quiet figure padding up and down the hallways of Mezes Hall in white socks and desert boots. He could easily have been the superintendent of the janitorial staff.

It took years for me to accumulate sufficient wisdom to come to him for teaching. Most of that wisdom was provided by the late Lee Willerman, who as head of the clinical program had gradually taken me under his wing and introduced me to behavior genetics. Lee was a towering intellect but no statistician, and when I showed some proclivities in that direction he would sometimes turn to me for help. I never knew the answer, so he would send me to John.

Despite John’s famously gentle demeanor, visiting his office was an intimidating experience. His door was closed, the outside of it covered in some cork-like material that I took to be soundproofing. One knocked, and a quiet voice said, “Come in.” John’s desk faced the door, and you sat in the one available chair. There was no small-talk. “Well,” I would say, taking a deep nervous breath, and proceed to describe the LISREL program that wasn’t running, sliding the big stack of green and white striped line printer paper across his desk. He would flip through it page by page, in silence, until finally his finger came to rest on a single number, perhaps a correlation coefficient in a large matrix. “That can’t be right,” he would say, and the meeting would be over. I do not recall an occasion when his diagnosis was incorrect.

Waldman’s experience

In contrast, the other of us (IDW) had never worked with or took classes from John Loehlin. I recall first meeting John at a conference on Statistical Methods for the Analysis of Change as a postdoctoral fellow in 1989. I had just begun working on the Minnesota Transracial Adoption Study and to my delight John agreed to have lunch with me. I had two pages of questions to ask him and get his advice on the analysis of longitudinal adoption study data. My concern was that I never would get through most of the questions. Imagine my surprise at John dispatching these questions so quickly—between the short time that the waitress took our order and the food arrived—that I spent the rest of the lunch watching as John ate his BLT.

John’s intellectual presence has had an impact on my work from the very beginning. I was influenced by various examples of his research and writing during my postdoctoral fellowship at the University of Minnesota and as a junior faculty member starting out at Emory University. To cite just two examples, John’s papers from the Texas Adoption Project and his work on Race Differences in IQ had a strong influence on my work on the Minnesota Transracial Adoption Study. And various editions of his seminal book Latent Variable Models have been a required text in my course of the same name for the past 20 years.

John Loehlin: Scientist, Mentor and Friend

The most important reasons for honoring John with this Festschrift transcend our individual relationships with him, extending to the aspects of John’s professional activities and personal characteristics that are so well known to our entire field. With regard to the former, John is a true polymath, making significant contributions to practically every area of behavior genetics. These include developing computer models of personality; multivariate statistics including but not limited to aspects of latent variable modeling; twin and adoption studies of intelligence, personality, and psychopathology; models for developmental behavior genetic analyses; issues concerning the magnitude and etiology of race differences in intelligence; and studies of the structure and etiology of personality both within US samples and cross-culturally. As if this weren’t enough, John is a poet, with several poems appearing in The New Yorker and several published volumes of poetry to his name.

John’s indelible personal characteristics may have contributed to the long wait for this richly deserved Festschrift. In a time of careerism and self-promotion John stands in stark contrast. Modest and unassuming, John raises reticence to a high art. His commitments are to the pursuit of truth and its transmission to others. John also has a sharp wit, although at times obscured by his shy nature. One must listen carefully. As IDW was finishing a sabbatical leave at IBG he asked John how he ever left Boulder after an earlier sabbatical of his own. John looked up thoughtfully for a minute and said “by returning to Austin”. Another time, IDW sat next to John at the BGA meeting banquet in Barcelona in 1994. Back in those days entertainment at scientific meetings could be quite elaborate. After a rather long wait for the food to arrive, several men dressed in bullfighter’s regalia appeared in the doorway, prompting John to remark, “It’s about time the pizza delivery guys got here”.

ET remembers another denizen of those Mezes hallways, the personality psychologist Arnold Buss, whose personality is the very opposite of John’s: voluble and extraverted, Arnie would get an idea in his head and rush from office to office, taking a poll on whatever issue had possessed him. He knocked on John’s soundproofed door, and when invited in, tried out his newest personality item: “What would you do to liven up a dull party?” There was silence as John considered the best answer. “Well,” he said, “I guess I’d leave.”

The contributions to this special issue reflect several distinct aspects of John’s research, but do not begin to exhaust the enormous breadth of his contributions. Jack McArdle describes John’s contributions to computer models of personality and multivariate statistics and multivariate behavior genetic analyses. Devon LoParo and Irwin Waldman draw on John’s work on measures of rearing environment similarity and tests of the Equal Environments Assumption in twin studies. Tom Bouchard describes John’s work in evolutionary explanations for the structure of mental abilities and a general cognitive ability factor. Matt McGue and colleagues honor his many contributions to our understanding the longitudinal behavior genetic analysis of continuity and change in alcohol use. Liz and Marcella Reitschel and Nick Martin demonstrate the use of Cholesky decomposition to test alternative models for the causal relations among Negative Emotionality, stressful life events, and depression. Sanja Franic, Dorret Boomsma, and colleagues build on John’s work to demonstrate the use of multivariate behavior genetic models (i.e., the common versus the independent pathway models) to test alternative psychometric models for the underlying structure of a multi-faceted measure and construct, in this case the Big Five Model of personality. Robert Plomin updates the many years of work he has contributed with John on the subject of gene-environment correlation. Lindon Eaves examines the many complications that arise in the detection and analysis of G by E interaction for complex traits.

The entire field of behavior genetics offers our profound gratitude to John Loehlin for the many professional and personal contributions he has made.