JSFiddle - React, Tailwind, and code Playground
JavaScript
var ancestry = [
{"name": "Emma de Milliano", "sex": "f","born": 1876, "died": 1956,"father": "Petrus de illiano","mother": "Sophia van Damme"},
{"name": "Carolus Haverbeke", "sex": "m","born": 1832, "died": 1905,"father": "Carel Haverbeke","mother": "Maria van Brussel"},
{"name": "Haverbeke", "sex": "m","born": 1842, "died": 1910,"father": "Petrus de illiano","mother": "Sophia van Damme"},
{"name": "Verbeke", "sex": "f","born": 1822, "died": 1915,"father": "Carel Haverbeke","mother": "Maria van Brussel"},
{"name": "Caro", "sex": "f","born": 1832, "died": 1888,"father": "Carel Haverbeke","mother": "Maria van Brussel"},
{"name": "Les eke", "sex": "m","born": 1822, "died": 1889,"father": "Petrus de illiano","mother": "Sophia van Damme"}];
function average(array) {
function plus(a, b) { return a + b; }
return array.reduce(plus) / array.length;
}
function age(p) { return p.died - p.born; }
function male(p) { return p.sex == "m"; }
function female(p) { return p.sex == "f"; }
console.log(average(ancestry.filter(male).map(age)));
console.log(average(ancestry.filter(female).map(age)));