“Coffee, Tea, and Mood Experiments” is a featured article in the special Coffee, and Tea issue (volume 26, number 4) of the Annals of Improbable Research. If you indulge in a cup of coffee or a cup of tea, inform yourself—in a tiny and certainly iffy way—as to what you might be doing to your emotions.
Read the article free, online. If you like it, make yourself a cup of coffee, spill a little for luck, and then maybe subscribe to the magazine.