Closer inspection of the ancient weapons revealed remnants of blood and bone that provided clues about how they were used.
The team reports its findings in the journal Antiquity.
The arrow heads were excavated from layers of ancient sediment in Sibudu Cave in South Africa. They dug through layers deposited up to 100,000 years ago.
Marlize Lombard from the University of Johannesburg, who led the research, described the approach she and her team took as “stone age forensics”.
“We took the [points] directly from the site, in little [plastic] baggies, to the lab,” she told BBC News.
“Then I started the tedious work of analysing them [under the microscope], looking at the distribution patterns of blood and bone residues.”
Because of the shape of these “little geometric pieces”, Dr Lombard was able to see exactly where they had been impacted and damaged. This showed that they were very likely to have been the tips of projectiles – rather than sharp points on the end of hand-held spears.