How can I re-iterate without limits in php

I have a function that retrieve the details of family member and can count the total of family member to the fifth generation. Below is my code snipped

function familyTree($id)
    {
        $total = 0;
        foreach(family($id) as $child){
            $total++;
            foreach(family($child->id) as $grand_child){
                $total++;
                foreach(family($grand_child->id) as $great_grand_child){
                    $total++;
                    foreach(family($great_grand_child->id) as $great_great_grand_child){
                    $total++;
                    }
                }
            }
        }
    
        return $total;
    }

My challenge is, how do I calculate the total number of family under the parent or anyone to infinity generation?

>Solution :

From the above comment by Giso Stallenberg, the correct answer should be the one below:

function familyTree($id)
{
    $family = family($id);

    $total = count($family);

    foreach(family($id) as $child){
        $total += familyTree($child->id);     
    }

    return $total;
}