A new study from Northwestern University shows what many mothers already know: their babies are a lot smarter than others may realize. （Credit: iStockphoto/Jason Lugo）

    ScienceDaily （May 7, 2009） - A new study from Northwestern University shows what many mothers already know: their babies are a lot smarter than others may realize.

    Though only five months old, the study's cuties indicated through their curious stares that they could differentiate water in a glass from solid blue material that looked very much like water in a similar glass.

    The finding that infants can distinguish between solids and liquids at such an early age builds upon a growing body of research that strongly suggests that babies are not blank slates who primarily depend on others for acquiring knowledge. That's a common assumption of researchers in the not too distant past.

    "Rather, our research shows that babies are amazing little experimenters with innate knowledge," Susan Hespos said. "They're collecting data all the time."

    Hespos, an assistant professor of psychology at Northwestern, is lead author of the study, which will appear in the May 2009 issue of Psychological Science.

    In a test with one group of infants in the study, a researcher tilted a glass filled with blue water back and forth to emphasize the physical characteristics of the substance inside. Another group of babies looked at a glass filled with a blue solid resembling water, which also was moved back and forth to demonstrate its physical properties.

    Next all the infants were presented with test trials that alternated between the liquid or solid being transferred between two glasses.

    According to the well-established looking-time test, babies, like adults, look significantly longer at something that is new, unexpected or unpredictable.

    The infants who in their first trials observed the blue water in the glass looked significantly longer at the blue solid, compared to the liquid test trials. The longer stares indicated the babies were having an "Aha!" moment, noticing the solid substance's difference from the liquid. The infants who in their first trials observed the blue solid in the glass showed the opposite pattern. They looked longer at the liquid, compared to the solid test trials.

    "As capricious as it may sound, how long a baby looks at something is a strong indicator of what they know," Hespos said. "They are looking longer because they detect a change and want to know what is going on."

    The five-month-old infants were able to discriminate a solid from a similar-looking liquid based on movement cues, or on how the substances poured or tumbled out of upended glasses.

    In a second experiment, the babies also first saw either liquid or a similar-looking solid in a glass that was tipped back and forth. This time, both groups of infants next witnessed test trials in which a cylindrical pipe was lowered into either the liquid-filled glass or the solid-containing glass.

    The outcomes were similar to those of the previous experiment. Infants who first observed the glass with the liquid looked longer in the subsequent test when the pipe was lowered onto the solid. Likewise, the infants who looked at the solid in their first trials stared longer when later the pipe was lowered into the liquid.

    The motion cues led to distinct expectations about whether an object would pass through or remain on top of the liquid or solid, the Northwestern researchers noted.

    "Together these experiments provide the earliest evidence that infants have expectations about the physical properties of liquids," the researchers concluded in the Psychological Science study.

    Hespos primarily is interested in how the brain works, and, to that end, her research on babies' brand new, relatively uncomplicated brains provides invaluable insights. She also is doing optical imaging of babies' brains, in which the biological measures confirm behavioral findings.

    "Our research on babies strongly suggests that right from the beginning babies are active learners," Hespos said. "It shows that we perceive the world in pretty much the same way from infancy throughout life, making fine adjustments along the way."

    In addition to Hespos, the co-investigators of the Psychological Science study are Alissa Ferry, a graduate student, and Lance Rips, professor of psychology, at Northwestern.

    來自西北大學的一項新的研究顯示，雖然很多準媽媽們都知道自己的寶寶非常聰明，但事實上他們的聰明程度超出了很多人的想象。（編輯：iStockphoto/Jason Lugo）

    科學日報（2009年5月7日）--來自西北大學的一項新的研究顯示，雖然很多準媽媽們都知道自己的寶寶非常聰明，但事實上他們的聰明程度超出了很多人的想象。

    從這項研究中許多準媽媽們好奇的眼光中我們可以看到，雖然寶寶只有五個多月大，但是他們就能夠區分出兩個很相似的杯子中的物體，一杯是水，另一杯是很像水的藍色固體物質。

    研究顯示，嬰兒在這么早的階段就能夠區分液體和固體。在此基礎上，越來越多的研究深刻表明，寶寶們的大腦在最初發育的時候并不是處于空白狀態，并不需要依靠外界力量來獲取一定的知識。

    "相反，我們的研究顯示，寶寶們在一些小實驗中表現出來的先天性知識令人非常驚奇，"Susan Hespos說道。"他們時時刻刻都在接受外界的信息。"

    Hespos是西北大學的一位心理學助理教授，他率先發起了這項研究，并將于2009年5月出現在《心理科學》這份期刊上。

    在這項研究的測試中，研究人員將嬰兒分為兩組，對于其中一組嬰兒，他們將一杯礦泉水來回搖晃以強調這杯水的物理特性；而對于另外一組嬰兒，他們則選擇了一杯類似于水的藍色固體物質，同樣來回搖晃來顯示出它的物理屬性。

    接下來，呈現在所有嬰兒面前的是，研究人員將這兩杯不同的液體和固態水進行輪流轉換。

    根據最近一項公認的研究顯示，嬰兒就像大人一樣，對于一些新穎的、意外的或者是無法預測的事物尤其關注。

    對于第一組嬰兒來說，相對于液態水的測試，他們觀察固態水的時間要明顯比觀察液態水的時間長。當嬰兒們看到不同于液態水的固態物質時，他們則發出一聲"哇哦"來表示對該事物更加感興趣。所以，在第一組測試中的嬰兒觀察液態水時表現出了相反的形態。對于固態水的測試，嬰兒們觀察液態水的時間則相對長一些。

    "同樣變幻莫測的是，嬰兒觀察事物的時間長短強烈印證了他們了解事物的程度，"Hespos說道。"他們長時間的觀察一件事物，是因為他們察覺到了事物的變化，并想知道這個事物將如何變化下去。"

    基于"運動暗示"理論，以及杯子里的物體是怎樣倒出來或者流出來這一線索，五個月大的嬰兒就能夠把固態物體和類似的液態物體區分開來。

    對于第二組實驗測試的嬰兒來說，寶寶們第一眼看到的其中一杯來回搖晃的固態物體，或者另一杯液態物體。接下來，兩組試驗中的嬰兒同時見證了一個事實，那就是這兩杯固態和液態物體分別被倒入一個圓柱形的容器中。

    事實證明，前面兩組實驗的結果是完全一致的。在接下來的測試中，當圓柱形容器中被倒入固態物體的時候，第一組試驗中的嬰兒則觀察液態物體的時間更長些。同樣地，當圓柱形容器中被倒入液態物體的時候，第一組試驗中的嬰兒觀察固態物體的時間更長些。

    西北大學的一位研究人員指出，這種"運動暗示"理論導致了兩種截然不同的猜想，那就是是否存在一種物質在液態或固態物體的頂部之間傳遞或逗留。

    這兩組實驗同時得出了一個結論，那就是嬰兒在早期階段就能夠估計出液態物質的物理屬性。"研究心理科學的一位專家推論了這一結果。

    Hespos最感興趣的是嬰兒的大腦是如何運作的，因此最后，她對于嬰兒大腦全新的、相對而言比較簡單的研究給人們提供了一個非常寶貴的見解。她還對嬰兒的大腦進行光學成象研究，并通過生物學上的方法證實了這一"運動暗示"理論。

    "我們這項基于嬰兒的研究強烈表明，嬰兒從生下來開始就具有主動學習的能力。"Hespos說道，"這同時表明，我們幾乎用同樣的一種方式來觀察這個世界，從嬰兒早期的階段一直延伸到我們整個的生命歷程，并在成長的道路上不斷進行自我調整和改變。"

    在西北大學，除了Hespos,還有很多人在研究這項理論，比如，心理科學研究院的合作研究員Alissa Ferry、研究生、以及心理學教授Lance Rips等。