To answer this question, we have to define altruism. Some discuss altruism at the biological level: selfish genes (Dawkins) or genial genes (Roughgarden and also)? Others examine altruistic motivation or behavior.
Some define altruism as helping others at no benefit to the self. How can an act have no benefit to the self? If one feels an urge to act, then taking the action is beneficial to the self because it completes the urge. So this is an unrealistic definition.
Others define altruism as helping that costs the self. How does one determine if an act costs the self more than it benefits the self? It is virtually impossible to do except in artificial, simplistic tasks as in laboratory experiments. This also seems to be an unrealistic definition.
Whether we focus on biology or psychology, the self is not a soloist. We are embedded --as if with sticky glue--in relationships, whether we recognize them or not. Our bodies and brains are systems of layered cooperation. Over 400 bacteria in our guts keep us alive. Even quarks are relational-they never exist alone.
For many years I listened to the rhetoric of the "self-made man," as if it was true that "I am a rock, I am an island" (frequently sung with my guitar in adolescence). As if! As if I pulled myself up by my bootstraps without help! What a delusion! But I had it for a long while.
Each self is situated in a particular set of relational networks, a life experience history, which cannot be escaped. And it can hardly be mapped out---do you know how much you have been influenced by others--by whom, when and how? I don't because I was not paying attention. I didn't notice how a teacher's compliment influenced which class I took the next year or how a friend's encouragement made me more confident. All the little influences day in and day out of hundreds of people over many years that shaped me and who I've become.
We are born as social units--there is no child without a mother. There is no mother without a father. There is no "me" without a "you". What I do influences who you are and who you become, whether I am aware of it or not. As globs of energy, my quarks are affecting yours.
On the other hand, as long as there is a self, there is self-interest. Every act entails self-interest because I cannot escape myself. What varies is the nature of the self interest. Is self interest only about me and at the expense of others? Or is self-interest inclusive of the well-being of others? And how far does the circle of concern extend?
I came back recently from a few days in Belgium carrying some gifts for my husband-several large bottles of Trappist beer. Some say when you care for your own, there is no altruism. But I could have not "cared" and brought my husband nothing. So I did think empathically of my husband's desires (beer!) and his flourishing (enjoyment). I "sacrificed" (yes, only mildly) for him by lugging the heavy (for me) case of beers through the long corridors of the U.S. border. This action was more altruistic than not doing it at all. Of course, my circle of concern with the beer did not extend very far, say to my neighbors or work colleagues. That certainly would have killed my back. But I did bring back boxes of chocolates for the people who work for me. (There's nothing like Belgian chocolate!)
Back to altruism. I consider altruism to be action that is more rather than less inclusive of others-- in terms of a sense of connection to and responsibility for the welfare of others (Ervin Staub's prosocial value orientation).
If I consider only myself in my decisions, it is not altruism but egoism.
If I am ruthless in getting what I want (hurting others), it is selfishness.
If I concern myself with facilitating the welfare of others (their flourishing) then there is at least a little altruism.
A little altruism is better than no altruism.
We can grow and develop in our expansive concern for others, in our sense of responsibility towards them, in our altruism. For example, we expect children to feel connected to known others and be concerned for their well being but we don't expect them to have as great a sense of responsibility as an adult might. On the other hand, we usually hope an adult will keep "in mind" how his or her actions affect many people who are "out of sight."
But altruistic action requires more than a sense of affiliation with others, concern for their well being and sense of responsibility for them. It also requires some efficacy at taking action (agency or effectance). In the case of the Trappist beer, I did have to think of the possibility of the action first and then I had to have some capability to carry it out (i.e., resources, time).
We don't expect children to be as efficacious as adults--to know as much as adults do about how to carry out actions to help others (influencing their ability to be virtuous). But even adults don't have efficacy in areas outside of their experience. A lot of damage has been done by well-meaning humanitarians acting in places outside of their experience (Easterly). When good intentions are not accompanied by concrete, contextual understanding more harm than good often results. Just because a solution works in your neighborhood doesn't mean it will work across the ocean.
So, effective altruism requires a prosocial value orientation but also experience and expertise in the area of helping. In order to help my neighbor, I need to get to know him and his situation. The help I give should be in an area I know something about. Say, like Walt Kowalski in the movie, Grand Torino. He knew a lot about fixing things around the house and helped others this way.
Did my parents raise an altruist? I have a prosocial value orientation, in many ways due to them. But my life experience and the expertise I develop will make the difference as to how effective I will be.