Pollster Khalil Shikaki said the drop appears to be due to a growing perception that such attacks have not advanced Palestinian interests.
"They are widely viewed as ineffective," Shikaki told a news conference.
Since mid-September, Palestinians have killed 28 Israelis and two Americans in stabbings, shootings and attacks using cars. At least 185 Palestinians have been killed by Israeli troops and civilians over the same period.
Israel says most were assailants, but has been criticized for what Israeli and Palestinian rights groups say has at times been excessive use of force.
Palestinian hopes for establishing a state through negotiations with Israel have dimmed after two decades of failed talks. No meaningful talks have taken place since hard-liner Benjamin Netanyahu became Israel's prime minister in 2009.
