Is sex a "want" or a "need"?
Jonas
We evolved to have sex and to masturbate as a species, not just for procreation, but recreation too, or else we wouldn't have been doing it for 10's of thousands of years until some men from the desert decided it is bad.
The health (both physical and mental) benefits are scientifically proven.
mekekelo The health (both physical and mental) benefits are scientifically proven.
I think scientific fashion changes over time. Currently, positive aspects of masturbation are stressed, but the negatives (like compulsion, soreness/oedema, loss of time and social life etc) are still there.
A doctor will say there is nothing wrong with masturbation ...up to the point where it starts to interfere with yours or someone else's life.
Vanessa We can consider it,needed to have a better health.
We've discussed this before, so all I'll say for sure is that my own health and happiness were increased greatly when I quit masturbation (or, more accurately, when I allowed myself to be prevented from it). I understand you have different view and experience and totally respect that.
Angelina advantages yes, i think so too but does that make it a need?
I think to the extent that sex brings us closer to others and serves to continue the species, it's definitely a need.
Masturbation, however, is by definition, a solitary activity. It's not needed at all and can go against getting out there, forming relationships, and living life!! 
That's what I found. Of course other people have other experiences and I respect this too.
Jonas Do people actually need to masturbate?
Here's a question:
If I feel horny is it better for me to go interact with my wife (in any way, doesn't have to be sexual) or for me to boot up porn and keep to myself until late at night?
An awful lot of people in the world are doing the latter! Is this healthy?
Jonas Surely no-one ever died from lack of orgasms?
Currently I am testing this theory... 
Gnaws own leg off through sexual frustration 
Vanessa We can consider it,needed to have a better health.
if health is the first priority i agree with you
Jonas A doctor will say there is nothing wrong with masturbation ...up to the point where it starts to interfere with yours or someone else's life.
exactly and i agree with you science is an ongoing process
Jonas Gnaws own leg off through sexual frustration
does not work because of my thighbands 
Jonas I think scientific fashion changes over time. Currently, positive aspects of masturbation are stressed, but the negatives (like compulsion, soreness/oedema, loss of time and social life etc) are still there.
A doctor will say there is nothing wrong with masturbation ...up to the point where it starts to interfere with yours or someone else's life.
Only happens if it is excessive.
Jonas We've discussed this before, so all I'll say for sure is that my own health and happiness were increased greatly when I quit masturbation (or, more accurately, when I allowed myself to be prevented from it)
Psychologically/emotionally,I can understand it;but physically,it is not what the scientists tell.
Jonas Masturbation, however, is by definition, a solitary activity. It's not needed at all and can go against getting out there, forming relationships, and living life!!
If done in a reasonable amount,it can help when single and help to know our body better.And it is often considered good,even if in relationship,nowadays.
Jonas Is this healthy?
Depends of the mood of your wife.
Jonas Currently I am testing this theory...
Why not have some with your girlfriend?
Angelina if health is the first priority i agree with you
Health is rarely used as a reason for doing it,but it is a good side-effect.
Vanessa Psychologically/emotionally,I can understand it;but physically,it is not what the scientists tell.
But psychology is also a science 
Jonas We have very different opinions and this is probably the result of our very different experiences with chastity. For you it's an unwelcome limit, for me a personal choice that freed me from masturbation.
i think at the psychological point the differences between volunteers and involuntaries are very big
Jonas We have very different opinions and this is probably the result of our very different experiences with chastity.
I think so,yes.
Angelina But psychology is also a science
But I don't know well if there is studies about psychological impact of a chastity belt for a willingly man(for a serious user,not a fetishist)...
Angelina i think at the psychological point the differences between volunteers and involuntaries are very big
Probably,and logical.
I agree,but it's not the case for many of us...
I randomly find this topic.
Sex is at the base of Maslow pyramid. While this as been criticised, in the author intention is definitively there. It’s a basic need. Sometime you will not see in the diagram, but it’s basically there
Also interesting to see that while sex is among physiological needs (with food and sleep), love, intimacy, are on the third level, so higher, where needs there are needs for belong.
Here is a good description
https://www.simplypsychology.org/maslow.html
Milord
While that pyramid theory is well established, it is by far not universally accepted.
And your claim that sex is the foundation is not correct. It is actually procreation that is underlying everything. Sex is just the most common concept. But if you read for examply 'Brave new world', you will realise that other models or society structures are by far not as unthinkable as might consider today.
Milord Sex is at the base of Maslow pyramid. While this as been criticised, in the author intention is definitively there. It’s a basic need. Sometime you will not see in the diagram, but it’s basically there
Also interesting to see that while sex is among physiological needs (with food and sleep), love, intimacy, are on the third level, so higher, where needs there are needs for belong.
From that same article:
Regarding the structure of his hierarchy, Maslow (1987) proposed that the order in the hierarchy “is not nearly as rigid” (p. 68) as he may have implied in his earlier description.
Maslow noted that the order of needs might be flexible based on external circumstances or individual differences. For example, he notes that for some individuals, the need for self-esteem is more important than the need for love. For others, the need for creative fulfillment may supersede even the most basic needs.
I would say sex in particular is one of those needs that is rather physiological in nature, but not important for the survival of the individual the way food, drink or shelter are. For the species, sure, sex matters as the vehicle of reproduction, which is why most humans experience a certain urge to engage in sexuality when they are equipped to meet the basic needs for potential offspring. But also, sexuality often serves as a supplement to love and intimacy for many, and a lot of people had a very good experience living fulfilled lives with minimal physiological sex.