Within the 14- to 15-year-old age group, one peer pressure variable emerged as a significantly more important predictor of girls than boys smoking. It is debated whether peer pressure or self-selection is a greater cause of adolescent smoking. Psychologist Hans Eysenck (who later was questioned for nonplausible results
 and unsafe publications) developed a personality profile for the typical smoker. Extraversion is the trait that is most associated with smoking, and smokers tend to be sociable, impulsive, risk taking, and excitement seeking individuals. Persistence
The reasons given by some smokers for this activity have been categorized as addictive smoking, pleasure from smoking, tension reduction/relaxation, social smoking, stimulation, habit/automatism, and handling. There are gender differences in how much each of these reasons contribute, with females more likely than males to cite tension reduction/relaxation, stimulation and social smoking.Some smokers argue that the depressant effect of smoking allows them to calm their nerves, often allowing for increased concentration. However, according to the Imperial College London, "Nicotine seems to provide both a stimulant and a depressant effect, and it is likely that the effect it has at any time is determined by the mood of the user, the environment and the circumstances of use. Studies have suggested that low doses have a depressant effect, while higher doses have stimulant effect." Patterns
A number of studies have established that cigarette sales and smoking follow distinct time-related patterns.
Smoking is often cited as an example of an inelastic good, however, i.e. a large rise in price will only result in a small decrease in consumption. Many nations have implemented some form of tobacco taxation. As of 1997, Denmark had the highest cigarette tax burden of $4.02 per pack. Taiwan only had a tax burden of $0.62 per pack. The federal government of the United States charges $1.01 per pack.Cigarette taxes vary widely from state to state in the United States. For example, Missouri has a cigarette tax of only 17 cents per pack, the nations lowest, while New York has the highest cigarette tax in the U.S.: $4.35 per pack. In Alabama, Illinois, Missouri, New York City, Tennessee, and Virginia, counties and cities may impose an additional limited tax on the price of cigarettes. Sales taxes are also levied on tobacco products in most jurisdictions. In the United Kingdom, a packet of 20 cigarettes has a tax added of 16.5% of the retail price plus £4.90. The UK has a significant black market for tobacco, and it has been estimated by the tobacco industry that 27% of cigarette and 68% of handrolling tobacco consumption is non-UK duty paid (NUKDP).In Australia total taxes account for 62.5% of the final price of a packet of cigarettes (2011 figures). These taxes include federal excise or customs duty and Goods and Services Tax.