[doomlaser]

Except that the structure of neurons and their physical connections with each other in the brain is very much physical, and we don't have the understanding of those systems on a conceptual 'software' level yet, so observations such as those made in this article are based purely on observation of the physical phenomenon.

[tlarkworthy]

Except that the concept of friends is non-physical

[doomlaser]

This article compares the physical structure of the brains of friends.