published by the Board of Scientific Affairs of the American Psychological Association: Intelligence is a property of the mind that encompasses many related abilities, such as the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn. There are several ways to more specifically define intelligence. In some cases, intelligence may include traits such as creativity, personality, character, knowledge, or wisdom. However, some psychologists prefer not to include these traits in the definition of intelligence. A widely researched index or classification of intelligence among scientists is intelligence quotient (IQ). IQ is a summary index, calculated by testing individuals' abilities in a variety of tasks and producing a composite score to represent overall ability, e.g., Wechsler Adult Intelligence Scale. It is used to predict educational outcomes and other variables of interest. Others have attempted to measure intelligence indirectly by looking at individuals' or group's educational attainment, although this risks bias from other demographic factors, such as age, income, gender and cultural background, all of which can affect educational attainment. Dissatisfaction with traditional IQ tests has led to the development of alternative theories. In 1983, Howard Gardner proposed the theory of multiple intelligences, which broadens the conventional definition of intelligence, to include logical, linguistic, spatial, musical, kinesthetic, naturalist, intrapersonal and interpersonal intelligences. He chose not to include spiritual intelligence amongst his "intelligences" due to the challenge of codifying quantifiable scientific criteria, but suggested an "existential intelligence" as viable. Religiosity The term religiosity refers to degrees of religious behaviour, belief, or spirituality. The measurement of religiosity is hampered by the difficulties involved in defining what is meant by the term. Numerous studies have explored the different components of religiosity, with most finding some distinction between religious beliefs/doctrine, religious practice, and spirituality. Studies can measure religious practice by counting attendance at religious services, religious beliefs/doctrine by asking a few doctrinal questions, and spirituality by asking respondents about their sense of oneness with the divine or through detailed standardized measurements. When religiosity is measured, it is important to specify which aspects of religiosity are referred to. According to Mark Chaves, decades of anthropological, sociological, and psychological research have established that "religious congruence" (the assumption that religious beliefs and values are tightly integrated in an individual's mind or that religious practices and behaviors follow directly from religious beliefs or that religious beliefs are chronologically linear and