The main objective of the study was to explain the effects of ethno-religiosity on fertility and contraceptive behaviour and to study the possible sources as well as the extent and nature of the variation in fertility and contraceptive behaviour among the major ethno-religious groups in Sri Lanka. In doing so, the study tested four hypotheses: a) Characteristics hypothesis b) Minority group status hypothesis c) Cultural hypothesis and d) Family planning accessibility hypothesis.

The findings of the study in terms of the proposed hypotheses show that fertility behaviour of the Sinhalese Christians and Sri Lanka Tamil Hindus (living outside Jaffna district) supports the minority group status hypothesis. Further, both the Sinhalese Christians and Sri Lanka Tamil Hindus in areas where they are numerically large had higher fertility than those who live elsewhere, suggesting that community influence has a stronger effect on fertility than individual desires. The differentials in ideal family size between the Sri Lanka Tamil Hindus living in the northern district and elsewhere further confirmed this. The analysis also showed that the fertility pattern of Moors, who displayed a negative relationship at higher level of education, but remained almost parallel to that of the majority Sinhalese Buddhists, confirmed to the cultural hypothesis, and that of the Indian Tamils did not fit any of the hypotheses.

Prof. Gyal D. Ness, the Chairman of the Doctoral Committee of the Author in his testimonial has stated as follows: "It should be noted that Dr. Abeykoon accumulated an excellent academic record in his class work, and wrote some of the best preliminary (comprehensive) examinations we have seen in the Department. He worked up the dissertation project, obtained the data and did the analyses under a very demanding but exceptionally well developed schedule. It should also be noted that completion of the Ph.D. in just over three academic years represents work much faster than the average. It is almost a record for swift completion. The dissertation received high praise from the committee members, especially for its discovery and demonstration of a "community" effect on reproductive behavior. Dr. Abeykoon was awarded a Hewlet Foundation fellowship by our Department for the first part of his studies, and he won a national competition for a Rockerfeller Fellowship to complete the dissertation.
Finally, my colleagues and I have been especially impressed with the personal and intellectual character of Dr. Abeykoon. He made the very difficult transition from senior official to graduate student with ease and grace. He displayed a combination of intelligence, industry and organization that was unequal among our students, and he did all of this with grace and dignity that made him especially popular in our Department. I share with my colleagues the highest regard for Dr. Abeykoon. We all have the utmost confidence in his intelligence and integrity."