Cheating was relatively stable as a student behavior between 1964 and 1997), but the type of cheating (from isolated incidents to collaborative efforts and from implicit to explicit) may have shifted.
It’s notable that this shift occurred before the impact of the internet.
Understanding student cheating is particularly important given trends that show cheating is widespread and on the rise. In 1964, Bill Bowers published the first large-scale study of cheating in institutions of higher learning. Bowers surveyed more than 5,000 students in a diverse sample of 99 U.S. colleges and universities and found that three fourths of the respondents had engaged in one or more incidents of academic dishonesty. This study was replicated some 30 years later by McCabe and Treviño (1997) at 9 of the schools who had participated in Bowers’s original survey. Although McCabe and Treviño observed only a modest increase in overall cheating, significant increases were found in the most explicit forms of test or exam cheating. (Source)