Sigmund Freud identified 3 stages of childhood development each of us goes through, which help shape our personality. These are commonly known outside the psychoanatylical world now - the Oral stage, the Anal stage, the Oedipal stage - and it's this last one which I think is particularly important when it comes to giving and receiving love. The theory defines that if our emotional needs were not met at the various stages, then the ego fragments at this point resulting in internal conflict for our life in the future.
The Oral stage is about trust and attachment, if our needs are met as an infant we learn to have trust in other people, and it's about what we can anticipate for our lives too, if we are in need will someone always come, are we worthy of other people's care, how does the world work, what's it like to be human.
The Anal stage involves the child's perceptions of automony and authority, independence, can I think and act for myself, is it safe to just have a go and learn new skills, can I cope with failure, can I produce something in life which will be valued by other people - will I have a sense of purpose.
The Oedipal stage is about co-operation and competition, it's about life being fair, it's about learning how to share how to connect positively with someone else's needs - learning empathy; being reassured when sibblings come along for instance, that our place in the family has not been taken by the new baby, that we have an important role in the family still. Seldom however do parents really understand the massive psychological impact of introducing another baby into the family, the approach tends to be focussed on telling the existing child they are growing up now, they don't need mummy so much, they can be more independent. The child rarely has the opportunity (or the words even at that age) to express their insecurities and the sense of injustice. Think of it this way...
Imagine a husband comes home from work and says to his wife 'I've got some wonderful news darling, we're going to have another wife! Yes, well you're quite grown up now aren't you, you don't need me so much and because you're such a big girl I'm going to give you your very own bedroom and we'll decorate it just as you'd like, you can pick all the colours - won't that be lovely! And the new wife will share my room, because she's very little and will need lots of extra care, just like you did when you first came here - but you darling, you can HELP me look after the new wife. Oh it's going to be so lovely, we'll all love one another very much and it's going to be even more wonderful than it is now!'
Immediately we can appreciate how hurt and insecure the 'old' wife would probably feel about that, and it's easy to understand why children might experience similar anxiety to the introduction of a new baby.
Similarly, if we introduce a new partner into the child's world, a step-mother or step-father, we could expect a considerable amount of anxiety to be experienced by the child, even if on the surface everything seems to be going fine.
Most of us will have experienced some painful conflict at the Oedipal stage, whether that was the arrival of a new brother or sister, first experiences of school or the introduction of a new 'mummy' or 'daddy' figure and most of us won't have had the opportunity to talk about our fears and jealousies and come to terms with them. Most likely, we'll have simply suppressed them and they'll only pop back up when we experience certain triggers - a spouse who starts to spend a lot more time at work or on the internet, a child who is keen to flee the nest - a man who drives straight into that car parking space we've been patiently waiting 10 minutes for, while the old biddie in the Morris Minor slowly manoevred her way out of it.
And I would suggest to some degree, most of us will experience resentment, envy etc when it comes to our own children, in fact the more we connect with our own children's needs to be cared for and the more positive parenting we ourselves offer, ironically the more likely it is that nerves will be touched deep within us, so deep in the unconscious that we have no rational explanation for why we feel anger say, when our little darlings make demands of us. Within us still, lives the child who's needs weren't always considered and that child is feeling 'This isn't fair, no-one cared if I had the christmas present I wanted, no-one cared that I was having problems at school, no-one read me a bedtime story!' But I'm aware that this perhaps makes uncomfortable reading for many of us, the idea that we could resent our own children who we love so much.
Now I would suggest the Oedipal part of our personality comes into play when we experience romantic love too, and the problem, as I see it here is, you can only love a partner as much as you love yourself. Many would dispute this I know, but I wonder how our unconscious feels about giving acceptance, compassion, kindness, patience and so on, to another person, if we can't give those things to ourself - and the sad reality is, most of us don't love and endorse ourselves anywhere near enough to keep us in the psychological black, as it were. So there we are, desperately trying to care for this partner, to tolerate the mood swings and the forgetfulness and the insensitive humour, and our inner lover is shouting 'Why are you being so nice to him - you don't make yourself a lovely cup of tea when you're in a bad mood! You don't just laugh it off when you forget to pick up milk on the way home - you rant and rave and slam things around the kitchen - you get really cross with yourself!'
So from a Freudian perspective, I believe the quality of your relationship with a lover, will only be as good as the quality of the relationship you have with yourself - and of course the quality of the relationship you have with yourself goes all the way back to your childhood.
Some have attempted to understand love in scientific terms, a big survey carried out in 2008 in conjunction with The Daily Telegraph concluded 'agreeableness' was the crucial ingredient when it came to long-lasting relationships, the ability for each partner to be kind, considerate, aware of one another's feelings and needs, but this only works really if both partners have the ego strength to put the other one first and not mind or resent that. Only around 15% of couples are genuinely happy, the research concluded, showing how hard it is to get things right.
Back in 1986, psychologist Robert Sternberg formulated his Triangular Theory of Love which illustrated how in order to achieve deep and lasting consummate love, a couple needed 3 elements to be present in their relationship - Intimacy, Passion and Committment. Where only 1 or 2 of these elements existed the couple could only enjoy a limited experience of love. Usefully his model offered clues as to how love may change over time between the partners.
All of these approaches are different and all seem to come to a similar conclusion, that the more in touch with yourself, and your own needs you are, the more likely you are to have a happy fulfilling relationship - but perhaps this works also, in part because the more self-aware you are, the more fussy you might be about who you give your heart to?