Table 1.

Demographic and smoking characteristics.

	Smokers (n = 24)	Nonsmokers (n = 20)
Agea	35.7 ± 9.9 (22–52)	30.1 ± 7.1 (20–45)
Education (years)a	13.7 ± 1.9 (8–16)	15.2 ± 1.3 (12–16)
Estimated IQb	106.6 ± 11.7 (87–127)	112.7 ± 11.6 (87–130)
Gender (female/male)	12/12	10/10
Cigarettes per day	17.7 ± 7.9 (10–40)	---
Years daily smoking	18.0 ± 10.6 (3–39)	---
Fagerström scorec	5.0 ± 1.9 (2–9)	---
Age of first cigarette	15.8 ± 3.6 (10–25)	---

Data are expressed as mean ± SD (range).

^aSmokers were older (t[42] = 2.1, p = 0.04) and less educated (t[42] = 3.0, p = 0.004) relative to nonsmokers.

^bGroups did not differ in terms of Wechsler Adult Intelligence Scale-Revised estimated IQ scores (t[42] = 1.7, p = 0.1).

^cFagerström Test for Nicotine Dependence (Heatherton et al., 1991).