Sure sounds like love to me ...
Functionally, I suspect love is an often temporary chemical imbalance of the brain induced by sensory stimuli that causes us to maintain focus on something that carries an adaptive agenda. Love is an adaptive feeling or emotion - like hate, jealousy, hunger, thirst - necessary where rationality alone would not suffice to carry the day. Could rationality alone induce a penguin to trek 70 miles over the ice in order to mate and then balance an egg on his toes while fasting for four months in total darkness and enduring temperatures of minus-80 degrees Fahrenheit and gusts of up to 100 miles an hour? And bear in mind that this 5-year-old penguin has just returned to the place of its birth from the sea, and thus has never seen an egg in its life and could not possibly have any idea what it is or why it must be kept warm. Any rational penguin would eventually say, 'To hell with this thing, I'm going back for a swim and to eat my fill of fish.'And to those with particularly challenging children, a not-so-temporary imbalance. If one loves long enough in the face of selfish logic, it would not be surprising were the brain to change fairly permanently.
This is a fascinating essay. Does the necessity of love indeed bound rationality? I don't quite agree. I think the author is confusing 'rationality' with 'self-interest'. Rationality is the capacity to reason, self-interest is one end to which reason is put. One may be exceedingly capable of logic, extrapolation, creativity and problem solving, and yet dedicate those ends to comrades, children, friends, society, or mate.
From the perspective of pure reason, I suspect a worm or even a rock is loved neither more nor less than one's self. Reason alone has no goals nor ends, any more than today's computers have goals or ends.