for interrogation. Fictional portrayals of torture as an effective interrogational method have fueled misconceptions that justify the use of torture. Experiments comparing torture with other interrogation methods cannot be performed for ethical and practical reasons, but most scholars of torture are skeptical about its efficacy in obtaining accurate information, although torture sometimes has obtained actionable intelligence. Interrogational torture can often shade into confessional torture or simply into entertainment, and some torturers do not distinguish between interrogation and confession. Methods A wide variety of techniques have been used for torture. Nevertheless, there are a limited number of ways of inflicting pain while minimizing the risk of death. Survivors report that the exact method used is not significant. Most forms of torture include both physical and psychological elements and multiple methods are typically used on one person. Different methods of torture are popular in different countries. Low-tech methods are more commonly used than high-tech ones, and attempts to develop scientifically validated torture technology have failed. The prohibition of torture motivated a shift to methods that do not leave marks to aid in deniability and to deprive victims of legal redress. As they faced more pressure and scrutiny, democracies led the innovation in clean torture practices in the early twentieth century; such techniques diffused worldwide by the 1960s. Patterns of torture differ based on a torturer's time limits—for example, resulting from legal limits on pre-trial detention. Beatings or blunt trauma are the most common form of physical torture. They may be either unsystematic or focused on a specific part of the body, as in falanga (the soles of the feet), repeated strikes against both ears, or shaking the detainee so that their head moves back and forth. Often, people are suspended in painful positions such as strappado or upside-down hanging in combination with beatings. People may also be subjected to stabbings or puncture wounds, have their nails removed, or body parts amputated. Burns are also common, especially cigarette burns, but other instruments are also employed, including hot metal, hot fluids, the sun, or acid. Forced ingestion of water, food, or other substances, or injections are also used as torture. Electric shocks are often used to torture, especially to avoid other methods that are more likely to leave scars. Asphyxiation, of which waterboarding is a form, inflicts torture on the victim by cutting off their air supply. Psychological torture includes methods that involve no