Living conditions in China have improved vastly since then, he said.

Van Crevel also saw tremendous changes in people's attitudes. In the 1980s, Chinese universities did not seem to be encouraging contacts between Chinese and international students, he said.

He felt very uncomfortable with the many restrictions, including a ban on lodging outside the campus. "Now the situation is completely different. Chinese and international students can exchange their ideas freely and the students are allowed to find accommodation elsewhere."

Van Crevel, who has been visiting China on an annual basis in recent years, said he now feels quite at ease in China, which was not the case in the past.

He said the academic circles in China are pretty open now. "All sorts of ideas are allowed and I can feel the atmosphere of free debate on the Internet," said the Chinese language and literature professor.

Back in 1986, his debate in class with the lecturer was seen as a serious "incident" by the university, he said. But today, heated debates are commonplace in classrooms of Chinese colleges, he said.

Van Crevel noted that there have been profound changes in ethics in China. For example, generation gaps in the 1950s and 1960s were far less evident than in the 1980s and 1990s, he said. The changes are a manifestation of the diversification of social values. However, it is difficult to determine whether these changes are positive or not, he said.