&gt;&gt;  I&#x27;d say it&#x27;s safe to say we&#x27;re primarily products of our unique environments and anyone brought up under the same conditions as us has a good chance of turning out just like us.<p>&gt; it&#x27;s pretty much accepted by this point that the answer is &#x27;yes, both matter&#x27;.<p>No, &quot;anyone brought up under the same conditions as us&quot; seems more likely to refer to shared environment than unique environment. It&#x27;s pretty much accepted by this point that while a lot of interpersonal variation can be attributed to the catchall &quot;unique environment&quot;, almost none of it can be attributed to shared environment (or in other words, the effect of an environment on one person has basically no predictive value for the effect of the same environment on a different person).