-Dhanush Veeramachaneni
Maybe you have heard people say, “Listen to your heart, not your mind” ‘Is it true or just a myth?'
I say listen to your Mind, and I will change your opinion too! ,
Before we jump into it:
Let us see what emotions are;
“Emotions are biological states associated with the nervous system brought on by neurophysiological changes which come through thoughts, feelings, behavioural responses, and a degree of pleasure or displeasure”.
What does love do to you i.e, how can you tell you are attracted to others:
Your dopamine (which is a rewarding hormone and a neurotransmitter) production goes up.
Your serotonin (which is a hormone that regulates your mood) production goes up.
Your oxytocin (which is also called a ‘’love drug’’ because it is released during empathy, trust, hugging, etc.) production also goes up.
Brain activity patterns associated with romantic love, shown with fMRI (Functional Magnetic Resonance Imaging), overlapped with regions expressing oxytocin receptors in the animal models, but definite proof for a role of oxytocin in human attachment is still lacking.
Hence, it might not be utterly outrageous to consider that the emotions one feels are majorly due to the hormones or neurotransmitters secreted by our brain. Still, think your heart’s saying something?

The neurons in the heart do communicate with the brain by providing feedback signals, which in turn may affect our emotions... So despite the presence of neurons in the heart, we can see that the heart does not have a mind of its own. Therefore, your heart doesn't really have much of a choice but it does affect your emotions.
While terms like “thinking with your heart,” “you’re in my heart,” and “heartbroken” make this pretty understandable, you really have your brain to thank — that’s where it all goes down.
The brain changes triggered by love certainly affect your mood and behaviour when these feelings are new, but some effects linger long past the first blush of love, continuing to strengthen your commitment over time.

Now coming to societal aspects - there is not much progress in Neuroscience for love right now but I guarantee there will be in the future, I can not say that what I’m saying is absolutely correct but all I am saying is that the BRAIN plays a bigger role than HEART in almost every way.
Hence, I say brain!
The write-up is good on a theoretical note.. But I can't agree with your rationale of emotions being biological.. If it were true, the disorders like bipolar, schizophrenia wouldn't still remain mysterious.. The harmonal secretions you cited were the effects and can't be accurate parameters of causality.. So the genesis of emotions is still mysterious and will be and that's the beauty.. Isn't it? 😊