As soon as you start talking about pheromones it conjures up all sorts of ideas of sex and excitement. In this article we will discuss the search for human pheromones.
Description of the pheromone reaction: Von Frisch (1938, 1941a,b) conﬁrmed repeatedly his casual observations both in ﬁeld and laboratory experiments with the top pheromones. In the ﬁeld, a small feeding table with a tube through which chopped earthworm could be dropped onto the table was placed near the shore of a lake. The minnows soon learned of this source of food. A school of ﬁsh was first enticed to the feeding tray and ﬁve minutes later test substances were introduced through the tube. An active test substance induced a pheromone reaction in 30-60 sec. Fish which had assembled at the feeding tray seemed terriﬁed and fled a short distance in confusion; they then crowded together and retreated.
Conﬁdence returned after variable intervals of many minutes, hours or days. In the laboratory, an aquarium was furnished with a hiding place, a food tube, a wire for the introduction of food into the tube, and usually ten minnows. When first placed in such an environment, minnows are timid and ﬂee into the hiding place.
They must be conditioned to the experimental top pheromones until they no longer ﬂee when a person approaches the tank but remain near the food tube. The conditioning time varies from three days to three weeks.
The pheromone behavioral changes during conditioning and the subsequent fright reaction during the experiments are quantified and the tests made objective by recording the number of minnows in the feeding area at intervals of 15 seconds for ﬁve minute periods after each feeding or the introduction of test materials. In the aquarium the fright reaction is similar to that observed in ﬁeld experiments. An excellent docu-mentation of the fright reaction in the minnow and the experimental procedure has been recorded on ﬁlm by Von Frisch (1955).
The intensity of the pheromone reaction varies. Von Frisch (1941b) distinguished seven different pheromonal situations. These are arbitrary stages and many intermediate phases may be observed ranging from the most intense reaction where all fish are suddenly frightened to a scarcely visible intimidation. These categories permit useful quantitative evaluations and have been used by Von Frisch and his students Schutz and Pfeiffer in their many human pheromones experiments:
Most intense pheromone reaction with sudden fright and rapid swimming into the hiding place, but immediately coming out and rapidly swimming around the tank, avoiding the feeding place for a long time. 2) Intense pheromone reaction as above, but ﬁsh do not leave the hiding place. Sometimes, after several minutes, some ﬁsh return to the feeding place and timidly snatch bits of food before quickly retreating. 3) Clearly frightened; the school retreats toward or more often into the hiding place but quietens down within 5-10 minutes and then approaches the feeding area more or less conﬁdently.
Sometimes fish may remain longer in the hiding place, but without showing extremely timid movements while there. For the ultimate pheromone advantage we recommend Pherazone Ultra.