A 2006 "Study of the Therapeutic Effects of Intercessory Prayer (STEP)" led by Harvard professor Herbert Benson was by far the most comprehensive and rigorous investigation of third-party prayer to date.[27] The STEP, commonly called the "Templeton Foundation prayer study or "Great Prayer Experiment", used 1,802 coronary artery bypass surgery patients at six hospitals. Using double-blind protocols, patients were randomized into three random groups, but without measuring individual prayer receptiveness. The experimental and control Groups 1 and 2 were informed they may or may not receive prayers, and only Group 1 received them. Group 3, which tested for possible psychosomatic effects, was informed they would receive prayers and subsequently did. Unlike some other studies, STEP attempted to standardize the prayer method. Only first names and last initial for patients were provided and no photographs were supplied. The congregations of three Christian churches who prayed for the patients "were allowed to pray in their own manner, but they were instructed to include the following phrase in their prayers: 'for a successful surgery with a quick, healthy recovery and no complications'.[28] Some participants complained that this mechanical way they were told to pray as part of the experiment was unusual for them. Major complications and thirty-day mortality occurred in 52 percent of those who received prayer (Group 1), 51 percent of those who did not receive it (Group 2), and 59 percent of patients who knew they would receive prayers (Group 3). Some prayed-for patients fared worse than those who did not receive prayers. In The God Delusion, evolutionary biologist Richard Dawkins wrote, "It seems more probable that those patients who knew they were being prayed for suffered additional stress in consequence: 'performance anxiety', as the experimenters put it. Dr Charles Bethea, one of the researchers, said, 'It may have made them uncertain, wondering am I so sick they had to call in their prayer team?'"[29] Study co-author Jeffery Dusek stated that: "Each study builds on others, and STEP advanced the design beyond what had been previously done. The findings, however, could well be due to the study limitations."[30] Team leader Benson stated that STEP was not the last word on the effects of intercessory prayer and that questions raised by the study will require additional answers.