If we had to run one quick sentence that encapsulated what the American ideal for attraction would be it's an obvious one, yet the question then becomes why it's so uncommonly achieved. The perfect combination for anyone is LOOKS (subjective) + CONFIDENCE (objective). We do love people who are beautiful, but we also love people who are simply themselves and aren't as burdened with negative thoughts of low self worth as the rest of us. This is really all you need to know when it comes to what makes you attractive or not, yet while confident ugly people battle against beautiful insecure people, to me, the more interesting question is why there seems to be a divide. In other words, why oftentimes can't beautiful people be confident? And Why do confident people so often not care about their looks.
For the first case, the common beautiful but insecure person.
The reason an beautiful person can quite often feel insecure is that they are rewarded very early on by other people for being good looking with esteem. They then often times consciously or unconsciously internalize and attempt to match their self worth based on those opinions they receieve. The problem occurs usually very early in their lives when consciousness starts to sink in more and more and other children become jealous of the positive esteem the beautiful person feels and so do things to undermine that beautiful person's sense of what others thinks of them. The beautiful person then has made the mistake of valuing what others thought of them more than an average looking person, because we live in a society that encourages us to seek validation through others rather than seek validation from ourselves. The beautfiul person suffers from this more so because to some degree they are able to positively build a positive self image based on the opinions of others. The problem, however, is that the beautiful person can always themselves doubt the positive attention they recieve as not being true in reality--reality being, of course, what we make it. Therefore, beautiful people often succumb to the jealousy their own gender feels for them and is often all to willing to put up with the abuse the opposite gender puts them through because they do not have a strong self concept that they themselves created. They are living off of attention both positive and negative and that's why even though they are beautiful, there's often something just a bit unattractive about beautiful people that very few beautiful people can seem to overcome. However, when you do find a beautiful person who is able to also create from within and have a strong sense of a self they created and enjoy then it's not unlikely you'll get someone akin to a movie star or an "it boy" or "it girl" This is the American ideal and very few would not find themselves attracted to the perfect combination of looks and confidence. (Sidenote: when people say they have a lot of personality they are talking about confidence...everyone has a personality but it's the extent to which you display your personality that seems you as having a lot of it, which someone who's insecure doesn't do as much.)
The second case is the very confident but visually unappealing person.
This man or woman often has a high level of confidence and energy that seems to flow out of them from mysterious origens. They need no validation really although they are fully capable of loving others and perhaps are more capable since they have no dependency on them but only love. They don't really think about themselves very deeply and seem to be more focused with finding the fun in life. Their sense of self is far more fixed and even if you tried to point out their flaws to this person, they wouldn't really understand the point of why you're saying what you're saying. I've noticed that girls especially desire to be this person, while oddly men tend to want to pretend to be the good looking guy with a harem of women. In reality, it's probably girls who suffer more from lack of confidence and men who suffer from lack of being physically attractive since, for women, the bar is often set much higher. For this reason, some women probably attempt to appear more confident and men attempt to appear more physically attractive to women beause of what they're attempting to mask. In any event, the confident person is really having their golden era now and for the past few years where someone who thinks they are great at soccer for instance, is more attractive than someone who actually is but doesn't believe they are. To bring this paragraph back to the thesis, people who don't feel like they have anything to prove have a harder time understanding the importance of appealing to others. The truth is that the Ideal lies in between LOOKS, which at the end of the day is really for others, and CONFIDENCE, which, at the end of the day, is really for you. You could have warts on your face and look like mr. potato head and still think you're Channing Tatum. Conversly, you could be Channing Tatum and think you look like Mr. Potato Head. Both would have their attractive qualities. However, in being of average looks lets say and having amazing confidence but also realizing that other peoples opinions do matter in terms of being attractive you will reach the ultimate ideal that few can resist. Think a girl with a super hot body and is super intelligent but wears moms jeans versus that same girl who is confident enough to wear yoga pants. Think the 20 year old novelist who also looks like an abercrombie and fitch model. In conclusion...
It's never just one thing...it's always a combination of things which create the Ideal.