In the early stages of Vatican II, a pontifical commission was established to study contraception. Membership consisted of 6 men, a one-sided way to study sex.
When the commission met the second time, there were 13 members, later increased to 15. Still all male.
Things changed at the 4th meeting in 1965. Membership jumped to 58 of which 34 were laity including 5 women. The final vote was 9 bishops of 12 (3 abstentions),15 of 19 theologians and 30 of remaining 35 members voted to change church teaching on contraception.
Paul VI ignored their advice. Humanae Vitae was a disaster.
We Catholics believe that church decisions are guided by the Holy Spirit, but how? Does the Holy Spirit speak only to the magesterium, or even only to the pope or does God act through the sense of all the faithful? The deliberations on birth control illustrates the consequences of a narrow outlook.