As looking of the hard work as researcher or teacher, the progress of the age of researcher can be an obstacle for given a supplement effort after 60 old years, however, some country fixed the age of retiree more than 65.
Sincerly, sometimes you find a researcher/ teacher who depass 60 years old but he still like his field and gives the maximum means that the age for him isnt an obstacle.. in the same time there is some researchers who have only 10 years or less of researchs but they don't give any new research!!! How you explain that?!!?
Retirement age remains the criteria for every professional personnel . As we know the researcher is a gate of knowledge ,knowledge has no limit as knowledge is a power . At retirement age individual can have his knowledge,experience in his period of time he may have gained his knowledge even from various sources at our present age .
It is in this line I have with me an article under captioned '' Retirement Age '' which I submit herewith for your kind perusal .
In Nigerian, professor retires at age 70. However, they are more effective and agile at age 65 and below. At age 65 till retirement, they are more useful as supervisors for research students, giving good mentorship, as adviser and maybe teaching advanced classes and organized lectures than in teaching lower classes because at this age we hear more of story than teaching though their experience is invaluable.