As noted elsewhere, Ginkgo Day is approaching (or is here, or has come and gone, depending on your location). Since my friend the Gastronomer complains “I have been wandering around New England quite for sometime and nobody told me about the ginko tree and nobody brought to my attention the tradition of the Ginko Day”, I think I will take this opportunity to explain the origins and two reasons for the continued observance of Ginkgo Day.

To the best of my knowledge (and I have spent quite a bit of time trying to prove myself wrong on this, and welcome any evidence that I am wrong), the tradition of Ginkgo day began with…me. Seriously. So far, every time I have talked to someone who knows about the Ginkgo Day traditions, I have been able to trace their knowledge back to me, through not too many intermediaries. I moved to this town (where there is a magnificent ginkgo tree perhaps 100 steps from my office) in 1984, and I have been unable to find any similar Ginkgo Day traditions predating this. (I did find, though, that ginkgo leaves have been used as “specific magic” against bookworms; this use is ancient, but unrelated to Ginkgo Day.)

The short version is this: The ginkgo tree (usually) loses all (or the vast majority) of its leaves on one day. This day is Ginkgo Day, the only holiday I know of where the determination of the date is independent of any human decision. The tree decides, and Ginkgo Day may be different from town to town, or even from tree to tree within a given town. The tradition I started (and I really don’t like saying that) is that if you catch a falling leaf on Ginkgo Day, it brings good luck. Oh, and you can catch leaves for other people–giving them the leaves will bring luck to them.

The long version is much more interesting, and is a tapestry woven from many, many different stories. I’ll just use one now…

“Dr. K.” Several years ago (but well after the tradition had momentum) I caught many leaves, and happened to give one to “Dr. K.”, a colleague of mine who had passed by and asked me what I was doing. (The short version does not adequately paint the picture of people standing underneath a tree, craning their necks skyward, lunging randomly at falling leaves, usually missing…) Dr. K. had recently been through a divorce, and thought she could really use some luck. Well…within the next week or two, she had met a man, a very nice man, an English teacher. She credited the ginkgo leaf. No, really. She told him about it, and gave him that same ginkgo leaf, laminated into a bookmark. A few months later, he carefully cut the leaf out of the bookmark, and presented it to her in a poem he had written, in which he proposed marriage. Of course, she accepted, and credited the ginkgo leaf. I have a copy of a poem he read at the wedding, crediting the ginkgo for their meeting and love. (The final copy, framed with that same leaf, is on the wall in their house.) The wedding cake had green ginkgo-leaf frosting; she wore gold ginkgo-leaf earrings. One of their wedding gifts was a set of crystal goblets etched with ginkgo leaves.

In subsequent years, I would see her at the tree on Ginkgo Day, catching leaves for friends. “I really do believe in this!” Two years ago, she moved out of state. At her new house, of course, they have planted a ginkgo tree.

For myself, I try my best never to miss a Ginkgo Day, but I do not share the view that it actually brings luck. It is a ritual, but not a superstition.

The science behind it…

In most operant conditioning experiments, reinforcement follows a particular behavior. Under some schedules (ratio schedules), reinforcement is delivered after a given number of instances of that behavior; under other schedules (interval schedules), reinforcement is delivered after the first instance of the behavior following a specified length of time. In both types of schedule, though, the subject (whether rat, pigeon, dog, monkey, dolphin, or person) must perform the specified behavior in order to receive the reinforcing consequence.

In 1947, B. F. Skinner tried something different; he delivered food to hungry pigeons “at regular intervals with no reference whatsoever to the bird’s behavior” [italics in original], and noted the resulting behavior. Most of the birds had developed stereotyped behavior patterns—repetitive movements which were quite obvious and consistent, turning in circles, or dancing with a pendulum-like movement, or a vigorous nodding of the head. It appears that the early movements the pigeons made were serendipitously followed by the delivery of food. This acted to reinforce the behavior, making it more probable that they were doing it again when the food was next delivered. A few repetitions of this, and the behaviors became stronger, even though at no time was the behavior necessary for delivery of food.

“The experiment might be said to demonstrate a sort of superstition. The bird behaves as if there were a causal relation between its behavior and the presentation of food, although such a relation is lacking. There are many analogies in human behavior. Rituals for changing one’s luck at cards are good examples. A few accidental connections between a ritual and favorable consequences suffice to set up and maintain the behavior in spite of many unreinforced instances. The bowler who has released a ball down the alley but continues to behave as if he were controlling it by twisting and turning his arm and shoulder is another case in point. These behaviors have, of course, no real effect upon one’s luck or upon a ball half way down an alley, just as in the present case the food would appear as often if the pigeon did nothing — or, more strictly speaking, did something else.” (1948)

When Dr. K. met her future husband shortly after the ginkgo leaf was caught (yes, I was the one who caught it, but human verbal behavior is easily able to bridge gaps like that), meeting him served as a reinforcer (a big one!) for the behavior of ginkgo leaf catching. There was, really, no causal connection between the leaf and her good fortune, but Skinner’s experiment demonstrates that no causal connection is necessary. And, while I would be happy to report that Dr. K. does not really believe there is any magic to this ritual, my conversations with her lead me to believe that she is quite convinced of its reality. Why shouldn’t she? All her experience has shown her that wonderful things come to those who believe in the magical power of the ginkgo leaf and act accordingly. We are, it seems, built to notice such connections, and to learn from them. Seeing connections is the basis for both science and superstition!

But what about me? Why do I, who claim not to believe in the superstition, spend my time under the ginkgo tree, running around like a fool, trying to catch falling leaves?

One possible explanation is that it is also superstitious conditioning, but without conscious awareness of the conditioning. In other words, the behavior of catching leaves has been reinforced, but not the behavior of believing in the superstition.

Another possibility is tied up in the concept of stimulus control. Briefly, stimulus control occurs when a behavior happens more frequently in the presence of a stimulus than in its absence. (We use this concept when we advise someone who is trying to quit smoking to change other things at the same time, so that the stimuli that used to prompt smoking would not be as salient.) I use Ginkgo Day as a day of remembering friends; I ask myself “if it really was the case that I could give someone luck by catching a leaf, who is important enough to do this for?” After all, there is no guarantee that I will see the tree on Ginkgo Day (since the tree, not the calendar, determines the date). There is no guarantee I will be there at the right time (one year, virtually all the leaves fell in under two hours—while I was teaching a class!). There is no guarantee that I will catch a leaf (at the peak of the fall, it is like a heavy snowfall, but if you miss the peak, it may take a while; I have seen people trying for over half an hour with no luck). So a leaf is a precious commodity. Deciding whom to send it to requires taking an inventory of all the important people in your life. In my opinion, if catching a leaf makes you think about the important people in your life, it is a good thing.

And giving a leaf to friends does not mean I actually think I am passing out magic talismans. It is really nothing more than an odd way of saying “I’ve been thinking about you. You are important to me.”

The nice thing is, I could spend an hour trying and failing to catch leaves (not that I ever have), and it would still be a success because I would have spent that time with thoughts of loved ones. On the other hand, if Dr. K. fails to catch a magic leaf, it foretells a bad year ahead!

I like my magic better.


5 Responses to “Superstition”

  1. thebehaviorist Says:

    Today is Ginkgo Day! (ok, technically, it is one of several Ginkgo Days in this town–other trees have lost their leaves already, but the magnificent ginkgo with the golden crown has chosen today.) I have already caught a few, and they are being pressed, for sending overseas…

  2. Elizabeth Popham Says:


    I have recently been searching for a letterpress company that could design a ginko leaf wedding invitation and this is why:
    My future son in law (unaware of the magic of the ginko tree), used to go to this majestical tree on his walks in Winston Salem. NC. He was a newcomer to the area and was astonished with the beauty of the large Ginko tree. The setting of this massive tree was in Old Salem. It was the largest and most beautiful tree there. As he rested beneath the boughs and leaves he was often inspired to pray to God whether or not he had made the right decision to move there since he was often lonely and missed his old friends from Indiana. Through many seasons he could be found under the tree’s branches and in the fall, the golden leaves. He prayed for love in his life, he had not had a good experience with his last girlfriend. I am almost positively sure that he may have examined the leaves with loving thoughts of his friends back home and a sense of hope that he would find that perfect leaf, perfectly knotched in the middle and golden (a new love), some day and bring them to this wonderful tree!
    It happened! He met a beautiful young maiden who turned out to be that perfect one!
    She walked with him often in Old Salem and they prayed under the ginko tree. This lovely violinist had been transplanted from NY temporarily and had taken a job with a busy quartet with residency in NC. After several months they began to experience a magical bond growing between themselves (love) and they were thinking and questioning is this the person I want to spend my entire life with in holy matrimony?
    A few months later, January 29, the young man engaged to his love underneath the ginko tree. The answer was yes and the wedding date is set for Decembers 13, 2008.
    I am not sure if I would say that the mysterious, beautiful tree and it’s leaves was the magic behind this union but I am sure that God intended it to be.

    Not being any expert on the scientific and psychological reasoning for the effect of the ginko leaf on human behavior I would have to say I believe God had his hand in the creation of the tree and it’s magical powers and therefore allowed this expression of love to exist.

    Thank so much for posting this and allowing me to reply.

    mother of the bride

  3. Zeljka Says:

    Oh….As beautiful as a lullaby…
    Thank you for sharing this lovely tale with us…

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  5. mia durr Says:

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