This paper reviews research dealing with problem solving abilities amongst Papua New Guineans. Studies concerned with individual intelligence tests, group intelligence tests, achievement tests, conservation measures, classificatory skills, and formal operational thinking are considered. Data are discussed which compared the performance of Papua New Guinean children and adults with people elsewhere, and with foreigners resident in Papua New Guinea. As well, important differences within Papua New Guinea related in particular to schooling and language-culture group are noted. By contrast with some previous conclusions about the cognitive skills of Papua New Guineans, it is concluded that while there are differences between some Papua New Guinean groups and groups from English speaking countries in problem-solving performance, developmental patterns appear to be similar. Thus, educated. Papua New Guineans eventually achieve the highest levels of formal thinking.