VIZCAYA, SPAIN—Teresa Fernández-Crespo of the University of the Basque Country suggests that late Neolithic and Chalcolithic societies were starting to become hierarchized, based upon data obtained from five megalithic graves in La Rioja and two in Araba-Álava, which together contained the remains of 248 individuals. “We propose that the people buried were intentionally selected,” she said in a press release. “The demographic composition of the megaliths displays significant anomalies with respect to a natural population of an ancient type. The bias identified, which almost systematically affects children under five, but certain adults as well, above all female ones, could be indicating that access to graves was restricted to those people who enjoyed certain rights and privileges only, against what is usually maintained in the traditional archaeological literature,” she said. Isotope analysis of the remains could shed more light on who was buried in the dolmens. Fernández-Crespo and her colleague, Concepción de la Rua, think that people of lower social status may have been buried in as-yet undiscovered natural caves, sheltered spaces under rocks, or pits. To read about similar structures in India, see "India's Village of the Dead."