Anybody ever heard of schizoid personality disorder? Picture this, it's like when your life is more of a passive observer than a active participant in life. Pretty much, life on difficulty mode. Sheesh!
It's different than AVPD and Autism. I met people who have Autism/Asperger's. They told me that they don't understand social cues but want too. AVPD is more like you want to make friends and be social but the fear of avoidance prevents them from enabling them.
How to spot a person with SPD? It's hard because like most things, it's a spectrum. Being emotionally cold and detached, anhedonia (lack of pleasure) and being indifferent is the main culprits.
Romance wise, people with SPD can fall in love and have romantic relationships. It's just they need a lot of space. A lot of emotional intimacy will cause a person with SPD to run for the hills!
Emotions? People with SPD DO have emotions. It's just...they FIND IT HARD to EXPRESS emotions. I used to be emotionally open in HS and College but after some traumatic events, I decided to keep to myself.