FLOWERS WORLD

The Emotional Niche – Both the Positive and the Negative
Can one really argue that positive emotion usually has survival benefits or conveys reproductive fitness? Despite early definitions of happiness or joy as a basic emotion, the continuing science of the evolution of emotion has emphasized the negative -- hostile and fearful emotions in animals and depression and hostility in humans (McGuire, 1993). A larger research literature reports on the stimuli that govern negative emotions as well as the patterns of response, secondary effects, and individual differences that emerge in their expression (for reviews, see Lewis and Haviland-Jones, 2000). It is clear that both plants and animals use defenses that elicit emotional fear or disgust reactions through the sensory modes of taste and smell, vision and audition. Snakes and spiders are not necessarily poisonous and the stinking, slimy mushroom may even be edible. It is not necessary that defense mechanisms be physically damaging, only that they produce an emotional reaction leading to avoidance or withdrawal. A plant or animal that can frighten or disgust a predator has gained fitness by exploiting an emotional niche. Withdrawal without physical contact is better than an active physical defense, which might lead to damage or death of the defending species. The ability to produce negative avoidant emotion in a predator has long been considered a possible defense and could be seen as the exploitation of an emotional niche.
That positive emotion could operate in a similar emotional niche has emerged recently but the evidence remains exploratory (Grinde, 2002; Seligman, 2002). Attraction mechanisms for plants have some socio-emotional features. For example, Hawk moths (Manduca species.) repeatedly visit Datura flowers (jimsonweed) for a hallucinogenic reward (Grant and Grant, 1983). Some species of orchids produce very little nectar and attract pollinators with perfumes. Orchid bees (Eulaema, Euplusia and Euglossa genera) collect perfumes/pheromones from these orchids into specialized pouches; they then use the perfumes as sex attractants. Other species of orchids mimic female sex pheromones and attract males who mate with the flower (Scheistl, et al., 1999). Interestingly, after “mating” the flowers then produce an anti-aphrodisiac pheromone (Schiestl and Ayasse, 2001). The well-known bower bird decorates its nest with flowers (Uy and Borgia, 2000). A number of bat-pollinated flowers emit a sulfur-like odor that mimics odors used in bat mating and social recognition (von Helversen, Winkler, and Bestmann, 2000). Many other plants provide non-nutritional chemical compounds, which insects can use for defense or sexual attraction (Weller, Jacobson, and Conner, 2000). There does not appear to be
a demonstration of plants providing socio-emotional benefits using similar chemical or visual mechanisms to humans.
The attraction to flowering plants reflected above may be related to positive emotion. Panskepp’s (2000b) research suggests that non-human species use positive emotion similarly to humans. “Tickling” rodents elicits high pitched “laughter.” This laughter is related to the appropriate neurological patterns for positive emotion, and is attractive to other members of the same species. Rats will prefer to approach a human caretaker who is a “tickler” over one who provides food and water. In other words, the immediate elicitation and expression of emotion even coming from another species is related to secondary social attraction effects. The secondary effects of positive emotion are demonstrated in a large number of behavioral domains for people as well as for rodents (Panksepp, 2000a). Positive emotion makes people appear to be more attractive, even sexually attractive and arguably, more likely to be approached socially. (Cunningham, Barbee, and Philhower, 2002; Otta, Abrosio, and Hoshino, 1996).
Both short and long-term expressions of positive emotion are related to secondary effects of positive mood. For example, cognitive processing that is inclusive and exploratory (Isen, 1987) often accompanies or follows positive expressions. Positive mood also improves memory processes (Isen, 1999; Levine and Burgess, 1997) and serves as a buffer against stress. Those who are induced to be positive will recover more rapidly from stressors (Folkman and Moskowitz, 2000; Fredrickson, 2000). Also, the long-term expression of positive moods leads to a prolonged involvement in an ongoing activity, and several researchers have argued that happiness is related to feelings of safety and would therefore be associated with social gathering and caring for infants (for reviews see Ekman and Davidson, 1994). Finally, happy people are more likely to get married, thereby establishing families (Mastekaasa, 1992).
Thus, happiness in humans facilitates both immediate and long-term social and cognate functions (Fredrickson, 2002; Izard and Ackerman, 2000; Panksepp, 2000a) and may lead to long-term survival benefits. Health benefits are often documented in laboratory studies of animals other than humans. For example, Poole (1997) suggests that unhappy animals are often physiologically and immunologically abnormal, and Hockly et al. (2002) found that the environmental enrichment of lab mice slowed the progression of Huntington’s chorea in genetically engineered mice. Environmental enrichment also is known to upregulate genes involved with neuronal growth (Rampon et al., 2000). There is a growing body of evidence supporting the need for a positive emotional environment for optimal health, social and cognitive processes. If positive emotion has these effects, then human emotional needs are a niche to which other species can adapt.
If flowering plants are exploiting a human emotional niche, it must be shown that they directly influence emotional states and thereby, also beneficially influence secondary cognitive and social behaviors. It is the goal of our research studies to demonstrate that some plants, notably domesticated flowers, have a strong effect on
emotional state and influence secondary cognitive and social behaviors.