IELTS 阅读素材：Research Using Twins
从一篇 IELTS 阅读文章中提炼段落大纲、写作/口语标本句、词汇搭配和可迁移论点。
核心观点
这篇文章围绕双胞胎研究展开，说明科学家如何用同卵双胞胎和异卵双胞胎来区分基因和环境的影响。它适合积累“科学研究、遗传与环境、健康、个体差异、技术如何改变认知”类 IELTS 素材。
文章最值得保存的观点是：人的性格、行为和疾病风险既不是完全由基因决定，也不是完全由生活经历决定。双胞胎研究先帮助科学家理解 nature and nurture 的关系，而表观遗传学又进一步说明，环境可能通过影响基因表达来塑造人。
文章结构
第一段说明双胞胎对生物医学研究的价值。同卵双胞胎几乎拥有相同的基因，所以如果他们之间出现差异，研究者通常可以从环境因素中寻找原因。
第二段进一步解释异卵双胞胎的比较价值。异卵双胞胎平均只共享一半 DNA，如果同卵双胞胎在某种疾病上更相似，那么这种疾病的易感性至少部分来自遗传。
第三段总结双胞胎研究的两条主线：一是研究同卵双胞胎之间的差异，以定位环境影响；二是比较同卵和异卵双胞胎，以衡量遗传作用。这一段把文章从具体例子推进到研究方法。
第四段转向历史背景。Francis Galton 在 1875 年提出用双胞胎研究遗传影响，并创造了 nature and nurture 这个表达。20 世纪 80 年代，分开抚养的同卵双胞胎研究让这一领域出现重要转折。
第五段介绍 Thomas Bouchard 的明尼苏达研究。研究者收集了大量问卷和测试数据，用“遗传度”这一统计概念来衡量人群差异中有多少可以由基因差异解释。
第六到第九段引出表观遗传学。文章指出，nature 和 nurture 之外还有第三种力量：表观遗传过程。它们会影响基因如何被表达，就像钢琴键盘上的琴键何时、如何被敲响，从而改变最终演奏出的“曲子”。
最后三段通过遗传学家 Danielle Reed 的评价收束全文。她承认很多特征是 hardwired，但也强调表观遗传学解释了许多双胞胎之间的差异。文章最后用“DNA 像钢笔写下的东西，表观遗传像铅笔写下的东西”这个比喻，强调有些因素相对固定，有些因素仍有改变空间。
写作可用论点
人的发展通常是先天因素和后天环境共同作用的结果。双胞胎研究证明，基因会影响疾病、性格和行为，但环境也能解释同卵双胞胎之间的差异。
Human development is shaped by both inherited traits and life experiences, so it is misleading to attribute behaviour or health outcomes to only one factor.
科学研究能帮助社会避免过度简单化的判断。过去有人认为心脏病完全来自生活方式，也有人把精神分裂症归因于糟糕的养育，但双胞胎研究让人们更谨慎地看待基因和环境。
Scientific evidence can prevent society from making simplistic judgements about illness, behaviour and personal responsibility.
环境影响并不只是外部条件，它可能深入到生物机制层面。表观遗传学表明，压力、成长经历或其他环境因素可能改变基因表达方式，从而影响长期健康和行为。
Environmental influences may affect people not only socially or emotionally, but also biologically by changing how certain genes are expressed.
对健康问题的理解越精确，公共政策和个人选择就越可能有效。如果某些疾病部分来自遗传，社会就不能只责备个人生活方式；如果环境也会影响风险，政府和家庭仍然有责任改善生活条件。
A better understanding of genetic and environmental risks can lead to fairer health policies and more realistic advice for individuals.
科学进步经常会推翻旧有的二分法。nature versus nurture 曾经像是一个二选一问题，但表观遗传学说明，二者之间可能存在桥梁。
Advances in science often challenge simple either-or debates by revealing more complex links between different causes.
可积累表达
untangle the influence of A and B：理清 A 和 B 的影响。
Researchers try to untangle the influence of family background and school quality on children’s academic performance.
nature and nurture：先天与后天。
Both nature and nurture play a role in shaping a person’s abilities and personality.
genetic code：遗传密码。
People may share similar genetic code, but their lifestyles can still lead to different health outcomes.
environmental factors：环境因素。
Environmental factors such as diet, stress and pollution can affect long-term health.
be rooted in heredity：根源于遗传。
Some medical conditions are rooted partly in heredity and partly in lifestyle.
the interplay of A and B：A 与 B 的相互作用。
Education outcomes are influenced by the interplay of personal effort, family support and school resources.
genetic makeup：基因构成。
A person’s genetic makeup may increase their risk of certain diseases.
in broad terms：大体上说。
In broad terms, public health policies aim to prevent disease rather than simply treat it.
shape our lives：塑造我们的生活。
Technology continues to shape our lives by changing how we work, learn and communicate.
a third component：第三个组成因素。
Apart from income and education, community support may be a third component that affects children’s development.
turn genes on or off：开启或关闭基因。
Some environmental pressures may influence whether certain genes are turned on or off.
a trailblazer：开拓者，先驱。
The scientist was a trailblazer in using large-scale data to study human behaviour.
口语可用素材
谈科学研究：
I find twin studies quite interesting because they show how scientists can separate the effects of genes and environment in a practical way.
谈健康与生活方式：
I don’t think health is only about personal choices. Some risks may be inherited, while others are linked to diet, stress or the environment people live in.
谈个体差异：
Even people who grow up in similar conditions can become quite different, because personality is shaped by a mixture of biology, experience and sometimes random factors.
谈科技改变认知：
New scientific fields such as epigenetics can change the way we understand ourselves. They show that genes matter, but they do not explain everything.
必背句
Human behaviour is shaped by the interplay of inherited traits and life experiences.
Scientific evidence can prevent people from making simplistic judgements about health and personality.
Genes may influence who we are, but the environment can also affect how those genes are expressed.
可改写成的 Task 2 题目
Some people believe that a person’s character and health are mainly determined by genetics, while others think they are shaped mostly by life experiences. Discuss both views and give your own opinion.