<P> Limitations of the original study comprise the inclusion of only middle - aged men and the lack of information regarding the diets of those subjects . While the latter could serve as a confounding variable, the former calls into question whether the findings can be generalized to the remaining male population or to the female population as a whole . </P> <P> Friedman et al. (1986) conducted a randomized controlled trial on 862 male and female post myocardial infarction patients, ruling out (by probabilistic equivalence) diet and other confounds . Subjects in the control group received group cardiac counseling, and subjects in the treatment group received cardiac counseling plus Type A counseling . The recurrence rate was 28% in the control group and 13% in the treatment group, a strong and statistically significant finding . </P> <P> Further discrediting the so - called Type A Behavior Pattern (TABP), a study from 2012--based on searching the Legacy Tobacco Documents Library--suggests the phenomenon of initially promising results followed by negative findings to be partly explained by the tobacco industry's involvement in TABP research to undermine the scientific evidence on smoking and health . The industry's interest in TABP lasted at least four decades until the late 1990s, involving substantial funding to key researchers encouraged to prove smoking to simply correlate with a personality type prone to coronary heart disease (CHD) and cancer . Hence, until the early 1980s, the industry's strategy consisted of suggesting the risks of smoking to be caused by psychological characteristics of individual smokers rather than tobacco products by deeming the causes of cancer to be multifactorial with stress as a key contributing factor . Philip Morris (today Altria) and RJ Reynolds helped generate substantial evidence to support these claims by funding workshops and research aiming to educate about and alter TABP to reduce risks of CHD and cancer . Moreover, Philip Morris primarily funded the Meyer Friedman Institute, e.g. conducting the "crown - jewel" trial on the effectiveness of reducing TABP whose expected findings could discredit studies associating smoking with CHD and cancer but failing to control for Type A behaviour . </P> <P> In 1994, Friedman wrote to the US Occupational Safety and Health Administration criticising restrictions on indoor smoking to reduce CHD, claiming the evidence remained unreliable since it did not account for the significant confounder of Type A behaviour, notwithstanding the fact that by then, TABP had proven to be significant in only three of twelve studies . Though apparently unpaid for, this letter was approved by and blind - copied to Philip Morris, and Friedman (falsely) claimed to receive funding largely from the National Heart, Lung and Blood Institute . When TABP finally became untenable, Philip Morris supported research on its hostility component, allowing Vice President Jetson Lincoln to explain passive smoking lethality by the stress exerted on a non-smoking spouse through media claiming the smoking spouse to be slowly killing themselves . When examining the most recent review on TABP and CHD in this light, the close relationship to the tobacco industry becomes evident: of thirteen etiologic studies in the review, only four reported positive findings, three of which had a direct or indirect link to the industry . Also on the whole most TABP studies had no relationship to the tobacco lobby but the majority of those with positive findings did . Furthermore, TABP was used as a litigation defence, similar to psychosocial stress . Hence, Petticrew et al. proved the tobacco industry to have substantially helped generate the scientific controversy on TABP, contributing to the (in lay circles) enduring popularity and prejudice for Type A personality even though it has been scientifically disproven . </P>

What are the personality types a b c d